Tacos al pastor, a delicious fusion food. The Mexican street dish par excellence, with an origin from across the world in the the Middle East. In the 20s a large number of Lebanese immigrants arrived in Mexico, bringing numerous culinary traditions with them, among which was the "shawarma" made with lamb meat. This preparation of lamb meat marinated with different spices, cooked on a spinning spit and served on pita bread, is the direct antecedent of the tacos al pastor.
Mexicans 'tropicalized' the recipe by changing the lamb for pig, adding a mixture of guajillo, chipotle, and ancho chiles to the recipe to create the marinade - a sauce that gives the characteristic color to the trompo (the big chunk of meat rolling by the fire), and finally by changing the pitas for corn tortillas.