Hello I am from Houston too. I live on the southwest side by the galleria. There is a vegan/veg restruant called the "Pepper Tree" that is awesome! It has been featured in some articles as one of the cleanest places in Houston and the food is awesome! I go there at least twice a month!
Good to know I'm not the only Texas vegan! :) I live closer to the Fort Worth area...Where there is a wonderful veg place called the Spiral Diner,(the only downside is it's over an hour away...). I don't know if you are familiar with the Stephenville area, but we are the "cowboy capital of the world",(i.e. we have lots of steakhouses and Mexican food restaurants around here.). Haha