There seem to be a lot of opinions on this topic and I certainly don't claim to be an expert. From what I've read, it seems like authentic Mexican tacos are soft corn tortillas filled with meat that has been marinated and grilled, and topped with fresh chopped onions and cilantro. Tex-Mex tacos are crisp corn tortillas stuffed with seasoned ground beef, cheese, shredded lettuce and tomatoes. There are a million variations on these two versions, one of which is the vegetarian taco recipe I'm bringing you today.