I am vegetarian and I feast when I am in the park. We eat at Carnation Cafe, and I tell them that I am vegetarian and the make sure my eggs are not cooked near the meats and bring my bacon out on a separate plate (my DH eats it), the gumbo at Royal Street is one of my favorite places to eat, and the pretzels.
At BB: the mushroom dish is okay, it was better with the garlic mashed potato than the couscous.
You can also eat Big Thunder BBQ, just order the veggie option. It is very tasty.

The veggie sandwiches are okay, they can be soggy at times (at carnation cafe and I think Blue ribbon bakery).
I actually don't actually have a problem eating most places. If they say vegetarian, they are, though not vegan. if you have a question about something that might be vegetarian (ie bean burrito), ask and the CM can tell you.
If you want to verify before you go, you can call the dinning reservation number and tell them you want to check on which every place.
When they changed the menu at BB, I called to check to see if it was veggie, and the called back after speaking to the chef to confirm.
Disney is very helpful and if given enough notice, any of the TS places can have something to make for you.
