I would create a veggie place - something like Cranks which used to be in Covent Garden but with a take out option. Or something like the soup/salad places they have in the states - Olive Garden, or Soup Kitchen I think they are called, where you pay a set amount and can have whatever you want/as much as you want, and a lot of it is veggie.
And now reading this thread has reminded me that I've only had a banana so far today and its ages til lunch!
ETA it's neither olive garden nor soup kitchen, i'm thinking of, it's Souplantation - must google before post!