Thursday night dinner in Reston VA
Three Thai Sushi for Thai (K-Mart shopping center).
Apparently Thai Luang has made a comeback, but I haven't been since the split a few years ago.
Sweet Basil Cafe would probably also work for you. Stoney's Kitbar also has some veggie options (and is now technically a chain, but the Herndon location was first of the two).
Euro Bistro has some veggie pies and apps. Cafe Montmartre in Lake Anne would also have options.
Near the airport and limiting yourself to Reston are two different things. Which are you looking for?
Karaikudi and Akshaya are both Indian restaurants with some exceptional food especially if you follow the recs: