Preheat grill or griddle skillet to medium-high heat. Lightly grease and add turkey burger patties. Squeeze a bit of lemon juice over each, then sprinkle with cumin, salt and pepper. Cook 3-4 minutes, until bottom is browned. Rotate and cook 3-5 minutes more until cooked through to an internal temperature of 165 F. Remove from heat.
Place cooked patties into each pita half (toasted if desired). Fill with desired amount of remaining ingredients to create burgers. Garnish with optional tzatziki sauce recipe here.