Small tortillas, either flour or corn, soft. Most of the authenticity comes from the seasoning on the meat used, I suppose... it's kind of like the difference between a 'real' chili and a chili-like stew, I guess? For those of you who are chili buffs? *shrug* Real Mexican food works with a broader and usually more intense set of flavors than you usually find in Taco Bell-style restaurants or home cooking.