Tuna Macaroni Bake 1 (10.75 ounce) can cream of mushroom soup 1 (3 ounce) package cream cheese, softened 1/3 cup milk 1 tablespoon minced onion 1 tablespoon mustard 1 cup elbow macaroni, cooked, drained 2 (6.5 ounce) cans tuna, drained, flaked Preheat oven to 350. In bowl, combine soup, cream cheese, milk, onion and mustard. In another bowl, combine macaroni, tuna and soup mixture. Spoon into buttered casserole. Bake for 45 minutes.