Combine all ingredients except for chicken, fillings, and sauce ingredients to make marinade. If it seems a little dry, add a little olive oil (a tablespoon at a time).
Add chicken, cover and refrigerate at least 8 hours, preferable overnight
Preheat a grill to medium heat. Remove chicken from marinade.
Grill chicken for about 10 minutes on each side or until fully cooked through. Serve chicken on pita and top with tomatoes and Shawarma Sauce.