Delicious Dinner (or Lunch?) on a Budget

Question of the week: Can you suggest a place for an affordable and delicious dinner?

"I'm going to cheat (again). I think the best way to get delicious food at an affordable price in London is to go for lunch and not dinner. There are dozens of excellent and other wise prohibitively expensive restaurants that do amazingly good set meals for lunch. The choice is often somewhat restricted and you should still expect to pay upwards of £15, but for the quality of food you get, and the chance to experience some of London's finest eateries, it really is worth it. "- Jamie

* Photo by Wootang01, used under Creative Commons, with thanks.