Later I went back to the oldest remaining Molina's location on Westheimer and looked for cheese enchiladas with chili con carne. I couldn't find the dish, until a waiter pointed it out on a separate part of the menu under the name "enchiladas de Tejas." Three enchiladas were smothered with chili and topped with a pool of yellow cheddar. I poured a small dish of chopped raw onions over the top. It was the best meal I have ever eaten at Molina's.

Just like everybody else, I too often make the mistake of going to old-fashioned Tex-Mex joints and ordering the mole poblano or grilled meats while ignoring the vintage dishes that they do brilliantly. Never order a steak at the pancake house — or at a Tex-Mex restaurant.

"Have you ever tried the old-fashioned tacos?" a friend asked me when we sat down at Matt's El Rancho in Austin a couple of years ago. I had often disparaged the place as hopelessly out-of-date, but when the tacos arrived I was astonished. Two tortillas were dipped in oil and wrapped around several thick slices of smoked brisket, placed on a hot griddle with a weight on top and then flipped and griddled on the other side. They came to the table crunchy but chewy, with chopped onions and cilantro, cold lettuce, tomatoes and guacamole to shove inside the taco. The wild variation in temperatures and textures is unbelievable. I have been back to eat those tacos at least a dozen times.

The old-fashioned Tex-Mex that's worth eating is the honest stuff that got lost in the fast-food frenzy and is currently making a comeback. And today, a fresh-fried taco shell, a lardy tamale or a well-made bowl of chili tastes shockingly new and different.

This is the way all the food tasted when Matt Martinez, Austin's "King of Mexican Food," first opened his restaurant in 1952.

The Martinez family is one of the oldest Tex-Mex dynasties in the state. Matt was the son of Delphino Martinez, who pushed a tamale cart on Congress Avenue in Austin before opening El Original in Austin in 1925. Matt Jr., a third-generation owner and chef and author of several Tex-Mex cookbooks, divides his time between Matt's El Rancho in Austin and his other restaurant, Rancho Martinez in Dallas.

But why did old-fashioned tacos like the ones at Matt's El Rancho disappear in the first place? Why did Tex-Mex go into decline?

In the 1950s and 1960s, Tex-Mex restaurants soared in popularity along with all kinds of casual new restaurants, Raul Molina told me. Many owners felt they had to compete with the emerging fast-food outlets and burger joints. And so they began streamlining the cooking process and cutting prices. Raul started making preformed taco shells by fastening tortillas to a bent coffee can. It saved a lot of time and money, but the tacos went ­downhill.

The chili con carne clung to the fat tamales like a meat sauce. Each tamale showed a thick streak of pork inside the tender layer of corn masa. "We have always made our own tamales," the waitress told me when I asked about them.

Tamales and chili con carne is the oldest dish on the menu at the Original Mexican Cafe in Galveston, which, as far as I can determine, is the oldest operating Tex-Mex restaurant in the state. The Original Mexican Cafe was opened by Raymond Guzman in 1916. Guzman had worked at several other Galveston restaurants, including the popular outdoor "Mexican Restaurant" at Electric Park, a seaside amusement park.

Tamales with chili con carne is so old-fashioned, people rarely order it anymore, but it was once the very definition of Texas Mexican food. I enjoy ordering the dish for its sense of nostalgia, but tamales just aren't what they used to  be.

I wish The Original Mexican Cafe were making tamales that were as rich and gelatinous as the ones they made 90 years ago, when the standard recipe for tamales included twice as much lard as it does today. To the detriment of flavor, modern Tex-Mex restaurants have cut back on the lard in tamales and refried beans in order to appease modern tastes. This is a huge mistake and one reason old-fashioned Tex-Mex is in decline. The food used to taste a lot better.

In my Tex-Mex Cookbook, I defended outdated ingredients like Velveeta and lard, which inspired one young food blogger in Portland to suggest that I had drank too much of my own "Tex-Mex apologist Kool-Aid." I completely understand his point of view. Properly made, old-­fashioned Tex-Mex includes lots of processed cheese and lard, ingredients that sophisticated food lovers rail against. But so what? Tex-Mex is a low-class cuisine that has been vilified by elitists throughout its history.