These make-ahead directions work best if you substitute an 8-inch square (2-quart) baking dish for the 1 1/2-quart casserole. Prepare recipe as directed above; do not bake. Cover with foil; freeze. When ready to use, do not thaw; bake, covered, at 350°F. for 1 1/2 hours. Uncover; bake an additional 10 minutes or until lightly browned and mixture is bubbly.