I agree with the PP. I haven't been to Jiko or Kouzzina, but have heard great things!
- Sanaa, Boma, and Tusker House are all great.
- Ohana makes a really great meal for vegans & vegetarians
- Although 1900 Park Fare was previously not great for veggies, if you can plan to go on a night when Chef TJ is working, he'll make you an awesome vegan meal.
- I really loved the vegetarian shepards pie at Rose & Crown, which I believe I've read they can make vegan. I believe they also have a vegan vegetable curry.
Always note on your reservation or call the restaurant to let them know that you are vegan. For buffets, a chef should be able to walk you around to let you know what you can eat.
There's also a great thread for vegan dining on here, with lots of great reviews.