Cover unbaked casserole tightly with plastic wrap; freeze until firm. Cover with foil. Freeze up to 3 months. When ready to serve, heat oven to 350ºF. Remove foil and plastic wrap. Discard plastic wrap. Re-cover casserole with foil. Bake 1 hour. Sprinkle casserole with cheese; bake, uncovered, 15 min. or until knife inserted in center comes out clean. Let stand 10 min. before serving. To decrease the baking time, thaw casserole in refrigerator overnight, then bake, uncovered, 40 min. or until done.