Place turkey wings and onion in a casserole dish; sprinkle seasoned salt, poultry seasoning, black pepper, and garlic on both sides of each wing. Pour 1/2 cup water into the casserole dish. Cover casserole dish.
Bake in the preheated oven until browned, 1 hour.
Stir cream of mushroom soup and 1 cup water together in a bowl; pour over turkey wings into casserole dish and return to oven, uncovered.
