Tacos are the national dish of Mexico, dating back to the Mexican silver mines of the 18th century, when the word taco referred to gunpowder that was wrapped in a piece of paper and inserted into rocks. It was used to excavate the precious ore from mines and was called tacos de minero or miner's tacos. Today, the word is widely known to signify the leading street food and fast food item in Mexico – thin, flat griddle-baked tortillas topped with numerous fillings, folded and eaten without any utensils.
In Baja, the topping consists of fried fish with cabbage and an acidic mayonnaise sauce. In Mexico City, sudados (sweated tacos) are the most popular option, filled with cooked and steamed meat. In Jalisco and Michoacan, they prepare carnitas, eaten in the morning or in the early afternoon, filled with deep fried pieces of pork that are sliced according to preference.
Similar is the taco de cabeza, filled with pieces of cow's head that was steamed for a long time, and the customers can choose from slices of eyes, brains, tongue, lips, cheek, or ears. Tacos are mainly made of corn, except in the north, where wheat flour is used more often.
They also differ in size, from the tiniest white tacos (blancas) to bigger ones, often made with blue corn. Most tacos come in pairs of two, in order to be able to hold all the flavorful and slightly wet ingredients. Some of them are fried until they become crispy and crunchy, in which case they're called tostadas.
As anything can be a filling, there is a version made with fried veins from dried chiles, usually accompanied by salt, a tasty treat called tacos de venas. However, the standard is ground or shredded meat, cheese, potatoes, or vegetables and a topping of onions and coriander.