Rancho Grande offers a vegetarian section of their menu featuring a vegetarian fajita of sauteed mushrooms, bell peppers, tomatoes, and onions. The only beans available in the restaurant are refried beans but the server swore they didn't use lard. Therefore the fajitas are easily vegan if the cheese and sour cream are withheld. Several other items on the menu (burritos, chalupas, enchiladas) are vegetarian but not vegan.
The food came in large portions (I only finished half) and was served very quickly and came steaming hot. The server was attentive and friendly, the atmosphere bright and cheerful, and the music lively but suitably quiet for lunch. I would rank this higher if the flavor had been more unique or if their were more vegan-friendly options.
That said, I would go to Rancho Grande again for their fajitas when visiting Buffalo for lack of other options in this not-so-progressive town.