SET the oven to 350°F. Spray a 13"x9"x 2" baking dish with vegetable cooking spray.
STIR the soup and milk in a large bowl. Stir in the macaroni, turkey, peas, half the cheese, half the onions and the black pepper. Spoon the macaroni mixture into the baking dish. Sprinkle with the remaining cheese.
BAKE for 25 min. or until the macaroni mixture is hot and bubbling. Stir the macaroni mixture. Sprinkle with the remaining onions.
BAKE for 5 min. or until the onions are golden brown.