Costra (“crust”) is a relatively recent taco phenomenon, with its history going back less than two decades to a Mexican City taqueria named Las Costras, located next to a boozy nightclub. On the most basic level, costras involve the use of cheese fried on a griddle before it is combined with the meat of one's choice.

Tacos were essentially a street food at this time since they were highly portable and cheap. In fact, Americans first became exposed to tacos through Mexican food carts in Los Angeles that were run by women called “chili queens”.