Prepare single pastry for a 9 or 10 inch pie pan

2 (10 oz.) boxes frozen spinach
1/2 c. chopped onion
1 c. sliced mushrooms (optional)
1 to 1 1/2 c. shredded Cheddar or Swiss cheese
3 eggs. slightly beaten
1/2 c. milk
1/4 tsp. nutmeg
1/8 tsp. pepper

Thaw spinach and drain all liquid; set aside. Saute onion and mushrooms in 2 tablespoons of butter. Combine all ingredients and pour into uncooked pie shell. (You may add more milk if mixture seems dry.) Bake at 350 degrees for 35 to 45 minutes or until knife comes out clean from center of pie. Serves 6. Variation: Pastry may be made for a top. Slit top pastry before baking.