The word 'pibil' comes from the Mayan 'pib,' the underground earthen oven the Maya used to pit-roast food long before pigs were even introduced to the Americas by the Spanish.
Pork is marinated in sour orange juice and achiote paste, wrapped in banana leaves, and traditionally slow-roasted in an underground pit until it shreds apart. Taco stands across the Yucatán pile it into tacos with pickled red onion.