I was in London for 3.5 days last week. Since I have gathered lots of great suggestions by browsing on this board, I figured I should post my experiences.
• Four Seasons in Chinatown
23 Wardour Street
I ate lunch there and ordered a rice plate with 2 BBQ meats: crispy skin pork, and roast duck. They gave me a complimentary bowl of soup du jour (pork and lotus root soup; delicious).
The pork was good, but the roast duck was even better. Unlike the roast duck I get in the US, their roast duck has a much more robust flavor and much less fat. And thumbs up for deboning the duck! Lunch was £8.20.
• Noodle Bar
33 Cranbourn Street (across the street from Leicester Sq tube station Exit 4)
The noodles here are so good that I ate here TWICE! Twice in 3.5 days. Although the English name of this place is simply called "Noodle Bar", its official Chinese name is translated as:
Authentic Lanzhou Ramen
Lanzhou is in the NW part of China, and it's famous for ramen (hand-pulled noodles).
Once I stepped inside the tiny eatery, I found the noodle chef at work, making the dough and hand-pulling the noodles.
My first meal here I actually ordered a bowl of dao xiao mian (knife-sliced noodles) with beef brisket. The noodles are hand sliced by the chef. Oh my. It was so good. The noodles are chewy and the broth is so flavorful, with tons of smashed garlic, spring onions, and cilantro. £6.50 for the bowl of noodle soup.
It was so good that I had to come back for another meal. This time, I ordered the ramen (hand-pulled noodles) with beef. While different, the noodles are just as good and I love the texture. The broth is the same. This was £6.
• Koya Udon in Soho
49 Frith Street
Based on suggestions here, I got a cold udon/hot broth version of mushrooms with walnut miso. Wow! The udon has fantastic texture - don't think I've had udon this good in the US, including NYC. And the walnut miso is wonderful - it comes in a paste and you mix it into the hot broth. I also ordered a poached egg for the broth. That came out perfectly poached. The total bill was £15.50
• Gelupo gelateria in Soho
7 Archer Street
This is another place I had to return for a second visit. On my first trip, I ordered a "2 scoop" cup, with persimmon sorbet and blood orange sorbet. The flavor of each fruit is bright and basically explodes in my tongue. It tastes creamy without the feeling of too rich. A 2 scoop cup is £3.
On my second visit, I got a "1 scoop" cup of ricotta/honey/coffee. Yes, all 3 ingredients mixed into 1 flavor. This isn't as amazing as the fruit sorbets. I think as they try to mix too many things into one, none stands out in the end. 1 scoop was £2.
• Kipferl Austrian Delicatessen near Barbican
70 Long Lane
Yet another place I ate here twice, on the same day! It's a small eatery with just 5 tables, as they mostly do take-away business. There isn't much of an Austrian or Viennese ambiance either, but the people who work there speak German.
I first ate lunch there - had a frittatensuppe and a kaesekrainer (sausage with cheese inside). The soup was excellent; just like the ones I've had in Vienna. The sausage was okay - I should have chosen a regular one instead of the cheese one, as I found it too rich and too heavy. Both the soup and the sausage came with wonderfully fresh rye bread. Lunch was £7.30
I came back here in the afternoon for coffee and cake. I had my favorite Viennese coffee - Wiener melange. It is as good as the melange (melanges?) I've had in Vienna. And it is served on a silver platter with a small glass of water and a piece of chocolate, just exactly like a Viennese cafe. For cake, I decided to get the Topfentorte (quark cheesecake). However, this was a disappointment. The texture was too crumbly and it fell apart, and it didn't have much flavor. Perhaps I should have stuck with the Sachertorte. Cake + coffee was £5.50