If your idea of Mexican food includes beefy burritos or gooey, cheesy enchiladas, you might be surprised to discover that you're actually eating Tex Mex food. In fact, here in the US, many of the foods we tend to think of as quintessentially Mexican—burritos, fajitas, chimichangas—actually aren't Mexican at all. So just what is Tex Mex food? And how is it different from traditional Mexican cuisine? Read on as we break down the delicious details.

What is Tex Mex?

Short explanation: Tex Mex is a type of fusion cuisine that blends elements of Northern Mexican cooking with American cuisine.

Long explanation: the term "Tex Mex" can be traced all the way back to the late 1800s, but back then, it wasn't used to describe food. It was the abbreviated name for the Texas Mexican railroad that ran through Southern Texas. After a while, people began applying the term to local Texans of Mexican ancestry too. These locals were rightly known as Tejanos, and their style of cooking was heavily influenced by the cooking traditions of North Mexico, as well as the ranching culture that straddled the borders of Southern Texas and Mexico. Their food even boasted some Spanish influence too, since the Tejanos lived and ranched (and cooked) in this area when Texas was still considered part of New Spain.

Initially, Tex Mex cuisine was notable for its heavy use of beef (which is not greatly used in Mexico, but was a staple of ranching life), as well as its use of wheat tortillas (corn is more common south-of-the-border). However, in the 20th century, the availability of cheap, processed foods also made an impact on this cooking style, which explains why yellow cheese has come to play such a big role in many Tex Mex recipes.

Tex Mex vs. Mexican Cuisine

So, how do you know for sure whether you're eating real Mexican food or Tex Mex? It's actually pretty simple: look at the ingredients. All of the following are staple ingredients of Tex Mex cooking, but not often found in authentic Mexican cooking:

• Yellow cheese
• Ground beef
• Flour tortillas
• Hard taco shells
• Canned tomatoes
• Black beans
• Refried beans
• Chili powder
• Cumin
• Sour cream

To illustrate the difference between an authentic Mexican taco and a Tex Mex taco, consult this handy table:

Classic Tex Mex Dishes

Fajitas

The term fajita once referred only to the cut of meat (strip steak) used in the dish, which was commonly fed to Mexican ranch hands, who prepared it over an open campfire. These days, it's the common name of any dish consisting of marinated and grilled meat, cut into strips, and served on a tortilla alongside grilled veggies (usually peppers and onions).

Chili con carne

Texas-style chili first showed up sometime in the 1850s as a convenience food cowboys carried with them on the trail. Dried beef, suet, chili peppers, and salt were pounded together and allowed to dry in the sun, and the resulting bricks could be thrown into a pot and boiled whenever necessary. The general population soon developed a taste for chili too, so much so that the first commercially-available chili powder was being manufactured in Texas by 1894.

Queso

There's actually a huge debate over who whipped up the first batch of queso cheese dip, but some historians point to Otis Farnsworth, who owned and operated a Mexican restaurant in San Antonio in the year 1900. But it wasn't until the invention of Velveeta cheese in the 1930s that the dish was made famous (and, some argue, perfected).

Nachos

Nachos were technically invented in Mexico in a town called Piedras Negras. The town happened to be located just across the border from Fort Duncan, and when the wives of some US soldiers crossed that border to do some shopping, they stopped at a small border restaurant for a bite. The restaurant was closed, but the manager obliged the women by inventing a snack of fried tortilla chips, cheese, and jalapenos. That manager's name? Ignacio "Nacho" Anaya.

Cheese enchiladas

Enchiladas were once nothing more than tortillas dipped in chili sauce and served from Mexican street carts. Today, in Mexico, you're much more likely to find enchiladas stuffed simply with meat and dressed in mole or another chili sauce, than you are the find the goey, cheesy, sour-cream topped versions popular in the US.

King ranch casserole

This dish—a casserole made of shredded chicken, tomato sauce, green chilies, and cream of chicken and cream of mushroom soups, was invented on the King Ranch, the largest ranch in Texas.

Burritos

The origin of the burrito is hotly contested, but some say it was invented by Mexican farm workers in California during the 19th century, who found the tortilla-wrapped meal easy to carry with them. In Mexico, you're more likely to find burritos stuffed simply with meat and beans, as opposed to the US, where rice, cheese, lettuce, sour cream, and any number of additional ingredients might make their way in.