Chop onion and garlic. Crumble beef into a frying pan and brown. Stir in onion, garlic, oregano, cumin, coriander, cinnamon, 1 teaspoon salt, 1/4 teaspoon pepper and tomato sauce. Cover and simmer 15 to 20 minutes.
Brush pitas with oil and gill quickly on both sides in a large frying pan (like grilled cheese).
Open pita. Fill with meat and serve.