Prepare the Marinade: In a large bowl, combine the yogurt, lemon juice, olive oil, garlic, tomato paste, and all the seasonings (paprika, cinnamon, oregano, ginger, salt, and pepper). Whisk everything together until well combined.
Marinate the Chicken: Add the chicken pieces to the bowl and toss to coat them in the marinade. Cover the bowl and refrigerate for at least 4 hours (or up to 24 hours) for the best flavor.
Thread the Skewers: When ready to cook, thread the marinated chicken pieces onto skewers. Optionally, add a wedge of onion to each skewer for extra flavor.
Grill the Chicken: Preheat the grill to medium heat. Grill the skewers for 5-8 minutes on each side, or until the chicken is fully cooked and slightly charred.
Serve: Serve the Shish Tawook with warm pita bread, fresh lettuce, and a drizzle of garlic sauce if desired.