DC Central Kitchen has joined On the Fly and another vendor, Delle & Campbell to form a cart party of sorts right off the 42 bus line. The three carts occupy a corner at 8th and H Streets in Chinatown. The carts offer completely different menus and have deployed a few tables so patrons can stand and eat outside on the nice days that remain before winter. It has been downright nice the last week or so and I've eaten at the carts twice.
Don't be surprised if the menus change a bit from time to time, but there is a vegan option at each cart. Yesterday I had the Mediterranean Picnic from the DC Central Kitchen cart. This cart is part of Capital Carts, an extension of their job training program. The Med Picnic is a vegan po boy, with caponata in sandwich form (I had to look it up first; essentially an eggplant dish). There are vegan desserts, but I haven't had one. The rest of the menu can be found here (pdf).
On the Fly was the most versatile and offered several vegan options. When I went last week, they offered organic pasta. Basically, you could tell the fellow behind the counter how you liked it, but I think the special that day had salmon as part of the dish. The rest of the menu is almost unbelievable for a cart (pdf). I need to try them all. Very vegan friendly. At the On the Fly cart at 7th and F Streets, you can also get a Julia's vegan empanada. They also sell my favorite drink of all time, Knudsen's Boysenberry Spritzer.
The final cart is from Delle & Campbell (as in Folarin Campbell; he helped GMU reach the Final Four a few years ago). D & C offers a great old vegan standby, the falafel sandwich. Tight. It's really good. Kind of smokey and burned. To D & C: I don't know it that was planned, but whatever happened in the kitchen, keep doing that.