Pizza Casserole

This is a family recipe that my mom made a lot when we were younger. It is an easy recipe that everyone loves and is one of my daughter's favorites!

1 - 4 oz. package Pepperoni, sliced

1 medium onion

1/3 C. Butter, melted

2 C. Swiss Cheese

1/2 tsp. oregano

1 lb. mozzarella cheese

1 - 15 oz. tomato sauce

1 - 4 oz. can mushrooms, stems & pieces

16 oz. spaghetti, cooked

Boil pepperoni for 5 minutes, drain well. Saute onion in 1 T.  butter. Pour remaining butter into 11 X 7  baking dish. Place cooked spaghetti into dish and toss to cover with butter. Cover with half of the tomato sauce, add in order, half of the swiss, all the mushrooms and onions. Sprinkle with oregano. Top with remainder of tomato sauce, swiss cheese, pepperoni and finally the mozzarella cheese. Bake for 20-25 minutes at 350 degrees.