“We can all thank [author] Diana Kennedy for inadvertently granting Tex-Mex its rightful place in food history,” wrote Robb Walsh in The Tex-Mex Cookbook. “By convincing us that Tex-Mex wasn’t really Mexican food, she forced us to realize that it was something far more interesting: America’s oldest regional cuisine.”

To this very day, arguments like Kennedy’s have been continually levied against puffy tacos, fajitas, and nachos—dishes that are accused of not being authentic to Mexican culture, an idea that hasn’t been helped by the genre’s ties to franchises like Applebee’s and TGI Friday’s. But Texans like Walsh, and scholars like Gustavo Arellano, know that it’s merely a false prejudice, not an essential truth. As Arellano said, “America doesn’t like mongrels, and that’s exactly what Tex-Mex food is: wonderful, beautiful mongrel meals.”

The truth is, that oozing cheese in every bite of gravy-smothered enchiladas, or the warm flour tortillas that arrive at your table, are what people consider home.

“America doesn’t like mongrels, and that’s exactly what Tex-Mex food is: wonderful, beautiful mongrel meals.”

“For Texans, it’s like our soul food,” says Lisa Fain, the James Beard Award-winning creator of the food blog Homesick Texan and a seventh-generation Texan who grew up outside Houston. After moving to New York for a magazine job, Fain not only had to grapple with the transition from slow-paced Texas to lightspeed NYC, but also the inability to find Tex-Mex anywhere. So, as a homesick Texan does, Fain started creating her own odes to her favorite dishes and sharing them with her friends—a project that eventually led to a widely read blog and two cookbooks. “Part of the reason we love it so much is because it’s a friendly cuisine—it’s a rare culinary experience that’s actually fun.”

But despite the cuisine’s recent spike in popularity outside of Texas (New York welcomed three Tex-Mex restaurants in 2015), many people who don’t hail from Lone Star State aren’t familiar with the hard-and-fast rules to eating this type of food, let alone its intertwined history. To catch you up to speed, we asked the Homesick Texan herself to help break them down for us. From the politics of the perfect margarita, to the primordial brown sauce that started it all, here are the 10 commandments of Tex-Mex.

1. Chili gravy is the Tex-Mex Mother Sauce.

According to Fain, “the key to Tex-Mex is the chili gravy: a brown-red sauce that’s made with chili powder in most Tex-Mex restaurants, but started as a sauce made with ancho chiles in San Antonio.” The gravy is most commonly smothered over a plate of enchiladas (pro tip: always go for the cheese version), but it can also be found atop tamales. The gravy is an extension of chili con carne, which was first introduced by The San Antonio Chili Stand in 1893 and is now the official dish of the state of Texas. Houston-based food critic Robb Walsh once said that chili gravy is the “mother sauce of Tex-Mex,” so if your enchiladas aren’t swimming in the stuff, you’re doing Tex-Mex wrong. (Photo: Lisa Fain)

2. The cheese is yellow.

While traditional Mexican food uses white cheeses like Oaxacan and cotija in its dishes, Tex-Mex prides itself on its use of good-ol’ processed American cheese. “The thing with Tex-Mex is it’s a Mexican technique with American ingredients,” notes Fain. Sure, you could use cheddar or Monterey Jack in your enchiladas, but you won’t get the same dreamy melt-job that can only be achieved with American. Plus, what would queso be without that unparalleled golden-yellow color? (Photo: Lisa Fain)

3. Chips and salsa will arrive before you even order a drink.

“You must have chips and salsa as soon as you sit down,” says Fain. “And the chips should be hot.” If they’re not there when you take your seat, expect them to arrive only a few seconds after. One of the most wonderful aspects of Tex-Mex is that you can gorge yourself on free food before you even get your entree. Consider it a bonus if you also get green sauce, which is made from tomatillos and originated in Houston. (Photo: Lisa Fain)

4. Your plate is overflowing with rice and beans.

Humble foodstuffs is the name of Tex-Mex’s game. In fact, Mexican rice and refried beans (fried in lard, preferably) are the perfect bookends to an especially saucy entree. “The rice and beans come on the same plate as your entree, so you can mix the whole plate or keep it separate— there’s really no rule,” says Fain. But you definitely should mix it all together. Just saying. (Photo: Yelp/Tracy R.)

5. The margaritas should be frozen.

The margarita is the go-to cocktail of Tex-Mex, and for good reason. It’s strong and refreshing, and you can knock back three without even noticing. And while you might think you want your marg “on the rocks” rather than “frozen” at a Tex-Mex resto, think again. “There’s a bit of a dispute about this, but frozen margaritas were invented in Dallas, so they are truly Tex-Mex.” There you go. (Photo: Yelp/Kayla K.)

6. Your entree plate should be oval-shaped and piping hot.

It may come as a surprise, but this is a very important element of the cuisine’s protocol. The white, oval-shaped plates lend themselves perfectly to the arrangement of an entree sandwiched between rice and beans. They’ve become an iconic marker of Tex-Mex, and as Fain notes, so has the the phrase “hot plate, don’t touch” uttered by waiters as they set it in front of you. (Photo: Flickr/Jeffrey W.)

7. Nachos have every ingredient on each chip.

Thanks to the missteps of sports bars and chains, most people associate nachos with a plate of soggy chips smothered under a mountain of 20 different ingredients. This, however, is not the Tex-Mex way. “The nachos should be made with the ingredients on each individual chip, that way you’re not left with a pile of plain chips at the bottom,” explains Fain. This architecture makes sense, since no one wants to take that last naked chip. (Photo: Liz Barclay)

8. You can never have enough pickled jalapeños.

Jalapeños provide a much needed kick—and in the Tex-Mex world, they’re pickled. Some platters even come with a little pile of them already on the plate, just waiting to be distributed evenly throughout the dish. But it shouldn’t end there. “I always get an extra side order of pickled jalapeños and completely cover everything with them,” says Lisa, who is also a pro at pickling her own jalapeños. (Photo: Flickr/getdirectlydown)

9. Tortillas are flour, and made in-house.

Listen, corn tortillas are great. They’re the perfect vessel for taco ingredients, hold up well against all the melted cheese in an enchilada, and make for fantastic chips. But flour tortillas reign supreme in the world of Tex-Mex. “In a Tex-Mex restaurant, flour tortillas should be house-made,” Fain states matter-of-factly, suggesting that this is something that should not be taken lightly. Do yourself a favor and get an order to-go—they’re perfect for making mini burritos with leftovers.

10. Ultimately, it’s comfort food.

Tex-Mex is greasy, spicy, and heavy—making it the perfect comfort food for Texans. When natives want a taste of home, they usually so straight for queso, nachos, and enchiladas. “Growing up, when my family went out to eat, we would go eat Tex-Mex,” says Fain. “Everyone has their local spot, and as soon as I get off the plane in Texas I make a B-line for my local Tex-Mex restaurant.” A good staff makes you feel like you’re part of the family. Platters are so big that your waiter expects you to have leftovers—and brings a to-go box without you even asking. Now that’s called service. (Photo: Liz Barclay)