I grew up in New Mexico and I'm allergic to a number of seasonings. The thing about Tex-Mex is that the seasonings are already added to the ground beef. I prefer "Gringo tacos" where you get the taco shells, then a number of bowls with shredded lettuce, diced tomatoes, ground beef, sour cream and guacamole. I use all but the guac in making my tacos, but that's just me. I also inherited my mother's intestines. One trip to Taco Bell, and "never again." With that said, there used to be a chain called "Dos Pesos" that made a similar thing to Gringo tacos, but instead it was fajitas, so, substitute the ground beef with sliced roast beef and the taco shells with soft flour tortillas. Dos Pesos got into a messy lawsuit with Taco Cabana and as a result of losing the lawsuit, Dos Pesos was absorbed into Taco Cabana. Taco Cabana does Tex-Mex, so no roast beef fajitas.