To prepare patties, combine first 10 ingredients. Divide into 8 equal portions; shape each into a 1/4-inch-thick patty. Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add 4 patties to pan; cook 5 minutes or until browned, turning occasionally. Arrange patties on a baking sheet. Repeat procedure with remaining patties. Bake at 400° for 5 minutes or until done.
To prepare sauce, combine yogurt and next 5 ingredients (through garlic). Spoon 2 tablespoons sauce into each pita half; top with 1 lettuce leaf, 2 tomato slices, and 1 patty.