As I've commented often, 'wait long enough and every type of cuisine will show up in Houston'. In Guadalajara and the state of Jalisco, there is a very popular late night, after the bar's have closed, sandwich called the torta ahogada. The two distinctive features are: a very hard, crusty salt bread called birote. And the tomato based salsa that one drenches the sandwich in. Now this sandwich has a reputation for being extremely spicy as a side bottle of tear inducing hot sauce comes with it so that you can up the spiciness to your personal taste. And this option is available, too.
At Guadalajara's Deli on Irvington, the chef/owner brings in authentic birote bread from Guadalara, 200 or so at a time, in order to bring this wonderful sandwich to Houston. I absolutely love it. But his menu also includes other specialties.
I first discovered "tacos de canasta" in Puebla. Vendors would show up with canastas (baskets) to sell pre-made tacos, tortillas filled with a variety of meats baskets, wrapped with cloth to keep them warm. This had the function of softening the tortillas. Tacos de canasta is a big thing in Mexico right now. And there is a version of this at Guadalajara's Deli for you to try. One person to order the torta, a second person to get the basket tacos.
Here is a (not so great) photo the crusty birote bread.