2 c. cooked spinach
1 c. skim milk
1 tbsp. grated onion
1/2 lb. fresh mushrooms, sliced
3 oz. cheese (skimmed milk), grated
1/2 tsp. powdered mustard

Line casserole with spinach. Place uncooked mushrooms on spinach. Combine remaining ingredients and pour over mushrooms and spinach. Bake at 375 degrees for 40 minutes.