To make the beef tapa, combine all the tapa ingredients in a bowl and marinate overnight or 2 days in a refrigerator for best result. Fry the tapa until cooked and browned.
To make the garlic sauce, just combine all the ingredients in a bowl, mix until smooth and set aside.
To assemble the shawarma: Heat the pita bread in an empty hot skillet until both sides are light golden brown. Set aside.
Lay the first pita bread in a plate and put 1 1/2 tablespoon of beef tapa, 1 tablespoon cucumber, 1 tablespoon tomatoes, 1 tablespoon onions, 1 tablespoon lettuce, 1 tablespoon grated cheese or sliced cheese and 1 to 2 tablespoon garlic mayo sauce on the center.
Wrap the filling with the pita bread like a log or a burrito. Do the same on the rest of the pita bread. Add hot sauce if desired.