Create a creamy and tangy chicken shawarma by using a food processor to blend together garlic, yogurt, lemon juice, and spices. The yogurt marinade helps tenderize the chicken while adding a delicious tangy flavor. Grill or roast the chicken until it's cooked through and serve it in warm pita bread with a drizzle of garlic yogurt sauce, fresh vegetables, and a sprinkle of sumac for an extra burst of flavor.