4 tbsp. butter
3 eggs
1 c. flour
1 c. milk
1 (10 oz.) pkg. frozen spinach (thawed and drained)
1 sm. onion (chopped)
1 tsp. salt
1 tsp. baking powder
1 lb. grated Cheddar cheese
1/2 c. mushrooms

In a 9x13 inch pan, melt butter. Mix remaining ingredients together and spoon into pan. Bake at 350 degrees for 35 minutes. Cool slightly before cutting into squares. Serve hot or at room temperature.