It’s true that tacos in Mexico are authentically made with certain indigenous cheeses. But with such a dynamic and adaptable dish there are few rules.
Something to acknowledge upfront is that cuisine - particularly food that has traveled from its original culture to elsewhere - resists restraint and social convention. Some diners may not prefer certain dishes, but if a chef can provide a reasonable rationale for combining tastes, textures and nutrients that some people find enjoyable, it’s a mission accomplished.
Calling more experimental dishes "fusion food" may seem like marketing sleight-of-hand. But it’s not unlike what happened when New World explorers took spices and potatoes back to Europe. Renaissance people loved their new food choices.
Cheese is a great way to illustrate this point. Cheese is largely a staple of Western diets, but take some to a remote village in China and you’ll face revulsion. Cheese is, after all, by definition a decaying dairy product. But in France fromage is practically an art form (but put shredded American cheese on a French fish taco, expect a disdainful sacrebleu response).
But this is America. Restaurant and home chefs and - especially - gourmet taco caterers are a bit more open minded, muchas gracias.
While it’s true that the taco - how do we put this? - has evolved since crossing the border northward about 100 years ago, that doesn’t mean that you’ll please discerning diners with a ridiculous bastardization of this fine dish. It helps to think through your creativity with a little historical background.
Start with what authentically are Mexican cheeses used in Mexican tacos in Mexico. This varies by region, but top on the list are Cotija (crumbled or grated) Añejo, Enchilado, Chihuahua, Penela, Queso Asadero and Queso Fresco. Mobile taco cart catering companies got this part right when they popped up in Texas and California about 100 years ago.
What you don’t see in that list are Cheddar, Swiss, Brie, Gouda or American cheese product. Some will argue that Monterrey Jack, Parmesan, and Mozzarella make reasonably good substitutes.
The authenticity snobs no doubt weep when foodie websites say you can use Greek feta (with pork belly, pineapple and mint), fresh Ricotta (with roasted poblanos), cheddar (with ground beef and pickled carrots) or Fontina (roasted garlic, roasted mushrooms and oregano) in tacos.
Others will suggest the margarita bar can smooth things over for everyone. Which is pretty standard in taco catering.
But to exclusively rule out Swiss or American cheese from all tacos from this time forth not only would upset a certain taco chain - one that singlehandedly introduced Americans to what a taco is back in the 1970s - but fails to recognize the history of food. Columbus fumbled his way across the Atlantic in search of black pepper, was initially disappointed with red peppers, but today the Anchos and Guajillos are beloved the world over and go just as well in a Tom Yum soup in Cambodia as on a pizza in Chicago and a beef brisket in Saskatoon. Humans like new things.
So be it. The point is there are so many different ways to make tacos that an event planner should entertain ideas with their taco caterer according to whatever the guests might really enjoy. There really are no rules.