At Matt's Rancho Martinez in Dallas, they have an appetizer called fried avocados. The deep-fried wedges are served with romaine lettuce taco shells, cilantro, slivers of carrots and jicama, and other fixin's. I got the idea from Vietnamese restaurants, said Marco Martinez, son of the late Matt Martinez Jr. The lettuce rolls are great for people on the Atkins diet, too; they put their fajitas on them. We use soy sauce on the fajitas—we borrow lots of things from Asian cooking. Making Viet-Mex salad rolls is sort of like making lettuce tacos. Put all the ingredients out on the table and let everybody roll their own.