El Taco Grande doesn't offer any mockmeats or soy cheese options, but their vegetarian tacos and burritos are quite tasty and filling. The food here is prepared freshly and feels home-cooked and labored-over, rather than just "assembled" at cheaper Mexican joints.
The portion sizes are huge and prices are fairly low. They use a ton of vegetables (broccoli, zuchinni, bell peppers and more) as the fillings for their dishes. Avocado is optional. Make sure to ask about their beans and rice, as I'm not sure they're vegetarian (lard and chicken broth, as usual).