2 pkgs. frozen French cut green beans
1 sm. onion, diced
1 (4 oz.) jar diced mushrooms
1 can (or less) water chestnuts, sliced
Parmesan cheese
Butter

Cook beans according to directions on package. Saute onions and mushrooms in butter. Combine beans, onions, mushrooms and water chestnuts in 9"x19" baking dish. Sprinkle with Parmesan cheese. Dot with butter and bake at 300 degrees for 20 minutes. Serves 6 to 8.