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    O2 Valley

    4.0 (29 reviews)
    Open 11:00 am - 9:00 pm

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    The popcorn chicken was soso.  Batter needs more spices .   #R1 Stir Fry Basil Chicken Bento. Was also only ok - no basil flavor
    Carolyn T.

    They took over spot where my fav noodle restaurant was ! Nothing changed inside ... could use a remodel . Food was good and portions large . Music was wierd and too loud though ! I'd order again .

    Dharma M.

    I've visited their Palo Alto location before, so I was excited to see this new spot open up. This location is a bit smaller than the one in Palo Alto, but it's a great addition to the neighborhood. ​The interior is simple. They have two touch screens for ordering, which makes the process incredibly simple and clear. While there is some seating and a standing area if you want to eat in, I noticed that most people (myself included) tend to order to go. ​I ordered the Basil Popcorn Chicken, and it did not disappoint: ​Texture: Perfectly tender and juicy. ​Flavor: Really yummy and well-seasoned. ​Quality: Even after the walk/drive home, it stayed nice and delicious while warm. ​Verdict: A solid, efficient spot for a quick snack or meal. I'll definitely be back to grab more chicken and order other dishes.

    Anna N.

    This is a Taiwanese bento box spot~ They give a generous portion which I was suprise to see! I ordered the basil popcorn chicken, grilled chicken cutlet bento, and the Taiwanese sausage bento. - The popcorn chicken was soo good!! Nice and crispy. The chicken was juicy and was cut very big. - I was slightly disappointed in the grilled chicken cutlet bento, I misunderstood what I was getting and thought it was a grilled chicken. I wasn't expecting it to be fried. The bento box also came with a cucumber & egg dish, napa cabbage, tea egg, and some minced pork on the rice. I thought the cucumber and Napa cabbage dish were very light in taste, almost bland, but it helped balance the grilled chicken cutlet.

    R3. Grilled Chicken Cutlet Bento
    Melissa C.

    I had tried the other location before so I was so excited to hear that O2 Valley opened another location in San Mateo! They are known for their bento boxes which can be great for takeout and packing for a meal. If you are dining in, you scan the QR code on your table to order. If you are ordering takeout, you order on the kiosk in the restaurant. The food was brought out quick within 5 minutes. The restaurant is a little small but still has several tables for seating. Items ordered: - Grilled chicken cutlet bento: The meat was on the sweeter side which I wasn't expecting, and I would've preferred a more savory flavor. But the meat itself was very tender and there were several pieces which made it worth it. Sides included rice with minced pork, cabbage, celery with chicken, and an egg. - Braised pork chop bento (boneless): I personally liked the braised pork chop better as it was more savory and tender. Came with the same sides as the other bento. Will definitely be coming back to enjoy more of their bento boxes which are very affordable for the amount that you get!

    Colleen L.

    So glad they opened an O2 here. Just like the Cupertino location, they offer the same basic, simple and fast Taiwanese bento boxes. They include the staples like popcorn chicken, chicken cutlet, pork belly with daily sides. You can order at the tablet kiosks or with the cashier. The wait time is very fast, you'll get your order in under 10 mins. The flavor here is a little lacking and can use some more seasoning. I ordered both the TS and popcorn chicken, both were a bit underwhelming. They have room for improvement and I'll try them again soon.

    Pork Cutlet Bento
    Cynthia M.

    Cute spot! I really wanted Taiwanese fried chicken so I had to come. We got a fried chicken and fries pork cutlet bento. SO much meat per order, very much appreciated!! Lots of breading and thin pieces. It felt like I was eating popcorn chicken strips with vegetable sides. Yummm. I love the vegetable sides in the bento! The vegetables made it feel like a full meal. The vegetable sides rotate. The menu pic has eggplant as a side, but we don't have that today! Very toddler friendly, because they have the red pepper powder on the side at the tables. My kid doesn't need to be scared he'll have a spicy bite! Love the spicy mushroom sauce they have near the water counter! It has fermented beans, mushroom, and red peppers! We wanted to eat there, but I didn't realize at the kiosk I have to choose the dining option to select 'eat here.' The dining option buttons for 'to go' and 'here' orders were placed in the same area as other food dish buttons, so I didn't see it for a while! I suggest to update the software so the dining option is the first or last question. Our food was ready so fast, I didn't even realize! We waited 10 minutes at the table when our food was just waiting at the counter. They also have paper bowls, but you'll have to ask for em! Excited to come back :)

    #R4 Popcorn Chicken Bento
    Sydney C.

    This place was so yummy! I the braised pork belly and it came with broccoli, potato curry, and rice with minced pork! The minced pork and rice was amazing and tasted like home. The braised pork was a little dry and chewy but I don't mind. The broccoli had garlic which I really liked and the potatoes were just alright. They have different sides depending on the day. The popcorn chicken was also pretty good as well. We came on a Wednesday afternoon and there wasn't that many people. Also a good amount of tables and theres a qr code you order off of. Service was pretty fast and easy to take out also portions are huge! The total came out to be around 40 bucks which is a little pricey but still good!

    Braised pork belly bento
    Dan F.

    Just opened about a month ago. This spot use to house Noodleosophy, then was taken over by another group serving the same menu, and now it O2 Valley. I have tried their other locations in the South Bay and thought they were pretty good. I love the concept of Taiwanese bentos and that you can pop in, order on the kiosk, and it'll be ready in about 5 minutes or less. Pretty convenient. I hope they stick around for a bit. I liked Noodleosophy's curry katsu noodles, but at least I can still get that in their Millbrae location.

    Tiffany C.

    O2 Valley is another South Bay gem that just opened in San Mateo! We ordered their full-size bento boxes for dinner, and the portions were very generous--definitely enough to share. Each bento came with 3-4 slices of pork chop, which made it feel like a great value. We're excited to come back and try more items on the menu!

    Megan S.

    This is a new favorite! Stopped in today for lunch with a friend and we will be back to try other options. The food came out so quickly and it was easy to order through the QR code on the table. The popcorn chicken bento was delicious and the sweet potato balls were as yummy and chewy as the last ones I had in Taipei! The tempura was a bit sweeter than expected but still delicious. I want to be back to try the cutlet and the mushrooms for sure. The portions were generous and everything we had was flavorful and fresh. Will definitely be back!

    Lo R.

    Love this place! Bento boxes are a generous portion size! The chicken is fried well and they give so much chicken! Delicious.

    Inside decor
    Raymond N.

    I went to O2 Valley in downtown San Mateo on the Saturday of its opening weekend. I actually didn't even know it was open until I saw an Instagram ad. I had to loop around for parking a couple times which was expected for a Saturday. Around lunchtime there were only two other parties waiting for orders and a few takeout orders were already ready on the shelf, though the shop quickly filled up after I ordered. The shop is a bit small, though there are quite a few tables and chairs available for dine in. Ordering is done on the kiosks by the counter as well as online on their site. I ordered the chicken cutlet bento and taro yogurt smoothie with boba, which I figured were safe options since I haven't been to any other O2 locations before. My order was ready approximately five minutes after ordering. The bento came with chicken, rice, egg, cabbage, and some sort of chicken and vegetable stir fry. The chicken cutlet was not greasy at all and seasoned very well, very similar to Taiwanese popcorn chicken seasoning. In general, I am not too big on veggies though I felt the provided side dishes complemented the chicken very well. The smoothie only comes in one standard size. I ended up ordering on a kiosk and this drink didn't have any customization options, though I noticed the online ordering allows for sweetness customizations; maybe kiosk ordering system can be updated to match the online system. Although a bit sweet since I wasn't able to adjust the sweetness, I thought the overall flavor of the drink was very good although I wish I could see inside the paper cup. Also, the boba is more on the firm side and a little too firm for my liking. Overall, I think O2 Valley is a nice addition to the 4th Ave side of downtown San Mateo. I do look forward to trying their other offerings whenever I am in the area.

    #R3 Grilled Chicken Cutlet Bento
    Kristen L.

    not too crowded on a weeknight, but lots of to-go orders. got the grilled chicken cutlet bento (definitely not grilled!), which came with braised pork rice, broccoli, eggplant, and an egg. the chicken was a bit too sweet for my liking, but was fried nicely; I enjoyed the braised pork rice the most. the place is not too big, but there are enough tables scattered around to enjoy the meal, with the occasional (and sometimes constant) sound of the electric fly zapper in the background.

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    1 month ago

    Unable to order in website for pickup, when trying to change 15% tip. Order disappeared and screen went blank then turned white. Malware?

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    3 months ago

    Great popcorn chicken. I loved the garlic version of it. Portion is great and the meat is lean

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    3 months ago

    Super large portion! Great taste too! Recommend. The basil popcorn chicken and fried radish are delicious

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    Ask the Community - O2 Valley

    Kajiken - Homura Aburasoba

    Kajiken

    4.4(1.4k reviews)
    0.2 mi
    $$

    No wait, got in immediately on a Saturday 1PM. Waited about…read more10 min until our food came. We sat outside which was nice on a hot day. Good portion, good level of spice, added some vinegar. Tasted deliciousssss and hit the spot.

    Kajiken hits the spot between comfort and pure gluttony! I typically do not love noodle places, but…read morethis is on another level. I have been to Kajiken twice now, and it has been absolutely delicious each time. It is located in downtown San Mateo, so it does not have its own dedicated parking lot. If you come on the weekend, it can be harder to find parking, and the likelihood of a wait is high. When it gets busy, there is a section outside for you to line up. The servers typically come out to the folks closest to the front of the line and hand them menus so they can decide what they want before being seated. When it is not as busy, you can walk in directly and request a table. The shop itself actually has a lot of seating, but there is always an influx of people, so it fills up quickly. The interior gives off a nice modern Japanese chic vibe. :) They also offer outdoor patio seating, which is great if you are trying to enjoy a nice day outside. I have tried both their Wagyu Roast Beef Aburasoba and their Soboro Aburasoba. The roast beef is tender and adds a nice chew against the silky noodles, while the soboro chicken is juicy and coats your mouth with a savory soy flavor. Additionally, I've had their karaage on both occasions I visited, and it was succulent! I love how the juice from the chicken balances with the generous amount of grated ginger and green onion. This place is definitely worth a try! If you can go on a weekday before the dinner rush from people getting off their 9-5 jobs, that would probably be the optimal time frame. I came here on a Wednesday around 6:15 PM, and it was not too bad until around 7 PM when it started getting busy.

    Photos
    Kajiken - Inside

    Inside

    Kajiken - Oroshi Ponzu Karaage($10)

    Oroshi Ponzu Karaage($10)

    Kajiken - Complimentary Accoutrements ($0) Vinegar, Chili Oil, Dried Garlic, Sesame seeds, & Chili Powder

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    Complimentary Accoutrements ($0) Vinegar, Chili Oil, Dried Garlic, Sesame seeds, & Chili Powder

    Dough Zone Dumpling House - San Mateo - pork soup dumplings   IG: lisaeatsf

    Dough Zone Dumpling House - San Mateo

    4.0(1.1k reviews)
    0.1 mi
    $$

    Very first time trying this place out! Wasn't very busy when I came in at around 4, so I didn't…read morehave to wait too long for the food to be served. The Green Onion Beef Pancake was very savory and moist. Definitely not a flavor I had ever experienced, but after the initial bite I began to enjoy it. Pairing it with Soy Sauce made it MUCH better! The High Tail Shimp and Pork Dumplings were very savory and tasty as well! And again, paired VERY well with the Soy Sauce. The Thai Milk Tea was very refreshing, though I didn't really care for the Rainbow Jelly. At least I tried it once, but I have a feeling I'd have enjoyed the Tea more without it. The atmosphere was nice and clean, and the service was superb! Will definitely come back to try some different dishes in the future!

    Came here on a Saturday afternoon for a snack. The restaurant was fairly empty so we were seated…read moreright away. We ordered at 5:20, just getting an order of pork soup dumplings and one order of spicy beef pancake roll. We thought this would be a quick bite, but it took 30min for the pork soup dumplings and the spicy beef pancake roll to come. There were no explanations of why it took so long but it was obvious the staff were stressed so we tried to be patient. However, there was another table behind us that asked the staff when food would come, as they were also frustrated, and the staff just snapped back with 'can you please just wait'. Seems like there's some operational issues at this joint or perhaps they're just very understaffed. In terms of the food, the dumplings were delicious but the pancake on the spicy beef roll were really greasy and overly done.

    Photos
    Dough Zone Dumpling House - San Mateo - Restaurant inside

    Restaurant inside

    Dough Zone Dumpling House - San Mateo - Dan Dan Noodles  担担面   IG: lisaeatsf

    Dan Dan Noodles 担担面 IG: lisaeatsf

    Dough Zone Dumpling House - San Mateo - Pork soup dumplings      IG: lisaeatsf

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    Pork soup dumplings IG: lisaeatsf

    Hunan Mifen San Mateo

    Hunan Mifen San Mateo

    4.3(75 reviews)
    1.6 mi
    $$

    Hunan mifen is a welcome addition of a very specific Chinese dish/cuisine in an area otherwise…read moredominated by pho, southern (Americanized) Chinese food with which is competes with in a no-frills, but satisfyingly delicious shop in the middle of San Mateo. This place was discovered by my wife while looking for noodle soups in the area. Me, I'm not particularly fond of super spicy. But their signature spicy beef has a very unique and addictive quality to it. Be forewarned - the chili oil the beef is bathed in is no laughing matter. We used to get warnings for the works to spoon in the chili oil a little at a time as it is a slow but powerful burn. But that's not what has be coming back. The main draw for me here is the blackened stinky tofu. They accompany this pungent snack with fresh cilantro. Peanuts and a sauce that match it so well. Might not be the best date food but it is delicious. Service is fairly minimal although staff are very informed and can answer questions. Order through the phone and for any toppings, you can get up and help yourself. Overall. This is probably one of my favorite noodle dishes when in the mood for something spicy or something quick. The portions here are also very healthy so come hungry.

    Hunan Mifen is another good spot worth trying if you love authentic Asian cuisine…read more I don't eat spicy food so I was happy that they have some dishes that is not spicy, I love the flavor of their broth, tasty not salty and it has a balance. I love that they have variety of appetizers and side dishes. Price is very reasonable for a freshly cook dishes. I would give them two thumbs up

    Photos
    Hunan Mifen San Mateo
    Hunan Mifen San Mateo
    Hunan Mifen San Mateo

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    Ox 9 Lanzhou Handpulled Noodles - Features on SF Chronicles- The one of a kind authentic hand-pulled noodles in the Bay.

    Ox 9 Lanzhou Handpulled Noodles

    4.3(702 reviews)
    0.3 mi
    $$
    Established in 2012
    Family-owned & operated

    Needed a lunch spot that wasn't a three hour wait (lol Whisper) - and this place seemed to call to…read moreus. Upon entering, I noticed that it is a sister restaurant to the Lazhou Noodles but before we could change our minds, the hostess sat us (lol). I went with the main beef noodle soup, and we also tried the dry noodles with spicy beef. I was expecting the food to be very similar to their sister restaurant - BUT the food here was so much better I was SO surprised. The broth tasted better, the noodles were higher quality, and the beef was also much more tender and had less gristle. it made me wonder if it was a fluke or if this location was just that much better as this restaurant was also much more crowded versus the other locations. I can't wait to come back and bring friends, and though San Mateo is parking is not as friendly, the food experience definitely makes up for it!

    One of our favorite go-to noodle houses whenever we are in the San Mateo area. It's not a huge…read moreplace but overall very clean. Noodles are hand pulled and made directly in front of you through a glass window where you can view your noodles being made. You can select from a variety of noodle textures and sizes. The noodle dishes are separated between soup and dry noodle versions. For the soups, recommend the Lanzhou hand pulled noodles soup or sichuan braised beef stew noodle soup. For the dry noodle, our favorite is the chilli oil noodles with wide noodles. For appetizers, the spicy wonton is really good. Their spicy sauce has just the right amount of kick and is mildly sweet. While they also serve dumplings, I kind of feel there are dumplings are just average --- stick with the noodles!

    Photos
    Ox 9 Lanzhou Handpulled Noodles - Features on SF Chronicle- the best bay ever in San Mateo!

    Features on SF Chronicle- the best bay ever in San Mateo!

    Ox 9 Lanzhou Handpulled Noodles - Proud to be featured on EATER SF in April 2023, the 25 must try essential restaurants in South Bay!

    Proud to be featured on EATER SF in April 2023, the 25 must try essential restaurants in South Bay!

    Ox 9 Lanzhou Handpulled Noodles - Chili Oil w/ Wide Noodles

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    Chili Oil w/ Wide Noodles

    O2 Valley - taiwanese - Updated May 2026

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