Put the olive oil in a bowl with all the spices and stir. Rub the meat well with this mixture. Put the meat in a tray, pour in a little water and cover with aluminum foil. Put it in a preheated 356°F (180 °C) oven for 1 hour, then remove the foil and bake another 10 min.
Make the garlic sauce: clean the garlic, put it in a mortar and pestle with a little salt and mash it. Transfer to a bowl, add the yoghurt, a little black pepper and stir until homogeneous. Grate the cheese, clean the tomatoes and cucumbers and cut them into thin slices.
Take the ready meat out of the oven, put it onto a wooden board and cut it into thin slices with a sharp knife. Heat a grill pan or BBQ grill, put the Arabic pitas to heat up for a few sec. on both sides.
Fill the pitas with sauce, meat, tomato and cucumber slices, a little cheese, then a little more sauce once again. Repeat for all of the pitas. Wrap them up and serve warm.