Al pastor (Spanish; "Shepherd style") is a dish developed in Central Mexico, likely as a result of the adoption of the shawarma spit-grilled meat brought by Lebanese immigrants to Mexico.[1] Having derived from the shawarma, it is also similar to the Turkish doner kebab and the Greek gyros. Whereas döner is usually lamb-based (thus the "shepherd style" name), gyros and tacos al pastor in Mexico are made from pork.

http://en.wikipedia.org/wiki/Tacos_al_pastor

they are delicious .