From a google search.
The cone of meat, marinated in yogurt and seasoning, is layers upon layers of meat (lamb, beef or chicken place on a spit and topped off with an onion and lemon. The spit is placed vertically in front of an open flame.
As the meat cooks it is turned. The shawarma chef takes his sharp knife in hand and cuts off paper thin slices of cooked meat which drop into a waiting tray below.
The cooked meat, salad and yogurt or hot sauce are placed in the pocket of pita bread or on a long toasted roll. Delicious!!!!!