In the good old days, Texans went to "Mexican Restaurants" and ate "Mexican food." Then in 1972, The Cuisines of Mexico, an influential cookbook by food authority Diana Kennedy drew the line between authentic interior Mexican food and the "mixed plates" we ate at "so-called Mexican restaurants" in the United States. Kennedy and her friends in the food community began referring to Americanized Mexican food as "Tex-Mex," a term previously used to describe anything that was half Texan and half Mexican. Texas Mexican restaurant owners considered it an insult.

But by a strange twist of fate, the insult launched a success. For the rest of the world, "Tex-Mex" had an exciting ring. It evoked images of cantinas, cowboys and the Wild West. Dozens of Tex-Mex restaurants sprang up in Paris, and the trend spread across Europe and on to Bangkok, Buenos Aires and Abu Dhabi. Tortilla chips, margaritas, and chili con carne are now well known around the world. In this series of articles, we reconsider Tex-Mex in light of its international reputation as America's most popular regional cuisine.

In the fourth article in this series ("The Authenticity Myth," by Robb Walsh, October 26), we looked at the many shades of authentic Mexican food available in Houston, and why searching for the real thing is overrated.

On the cover of Chuy's menu, a matador swishes his cape in front of a Cadillac sporting a flame paint job and a longhorn hood ornament. In the lower right it says, "Fine Tex-Mex." I get the Comida Deluxe Dinner. The guacamole retains the shape of a miniature ice cream scoop, the refried beans are crusty, and the queso is pure Velveeta. The Tex-Mex sauce on the very cheesy enchiladas is made of ground beef and whole chiles, and is much more intense than old-fashioned, flour-thickened chile gravy. The margarita is fuerte, the hot sauce is picante, and the chips are served slightly caliente -- this is Tex-Mex the way el Señor intended it.

Chuy's on Westheimer celebrated its tenth anniversary this year. From my two-tone vinyl booth, I look out over a dining room furnished with 1950s-style chrome dinettes. The silverware comes in a white paper bag that says "Sanitized for Your Protection" on one side and offers a Catholic, Protestant and Jewish grace on the back. With its painted fish mobiles, broken-tile frescoes and shrine to Elvis Presley, Chuy's is not your typical Tex-Mex restaurant. Or is it?

The first Chuy's was opened on Barton Springs Boulevard in Austin in the early '80s by two Anglos named Mike Young and John Zapp. From the beginning, the black velvet paintings of Elvis on the walls and the retro "Air-Conditioned" painting of a penguin with a scarf and earmuffs made it clear that Chuy's was a tongue-in-cheek send-up of old-fashioned Tex-Mex restaurants.

I stopped by Chuy's offices near the original restaurant in Austin one afternoon to look through their archives. Chuy's is the first "self-proclaimed Tex-Mex" restaurant I know of, and I was interested in finding out when it started using the term.

In 1982, its first menu boasted, "Chuy's, Comida Deluxe." In 1986, the words "Tex-Mex Deluxe" replaced the original phrase. "We embraced the term "Tex-Mex' pretty early," says Mike Young. By 1986, the term regularly appeared in the national press, he remembers, although he believes people in the rest of the country were mistaken about what Tex-Mex really meant.

To Young, who grew up eating Tejano food in the Lower Rio Grande Valley, Tex-Mex was a style of restaurant cooking he first encountered in San Antonio; its signature dish was a cheese enchilada in chili gravy, topped with raw onions. But in the view of the general public, Tex-Mex had become a much broader category, and Young took note of it. Then he went along with it.

Chuy's was one of first restaurants in Texas to call itself Tex-Mex, but it was not the first in the world. That distinction, like so many other culinary honors, belongs to the French. To the vast amusement of Texans, Tex-Mex became the hottest food trend in Paris in the 1980s. By the early 1990s, Tex-Mex restaurants were springing up all over the world.

Cafe Pacifico's cheese enchiladas came cloaked in a rich red chile colorado sauce. But it was the cheese itself that captured my attention -- sharp, tangy and perfectly melted with the aroma of a Swiss fondue. It was the best cheese enchilada I had ever had. Which was quite a surprise considering the restaurant's location in the Montparnasse section of Paris.

"What kind of cheese do you put in these enchiladas?" I asked the waitress.