1 (4 oz.) pkg. sliced pepperoni
1/3 c. butter, melted
1 c. grated Swiss cheese
1 lb. Mozzarella cheese
1/2 tsp. oregano
1/2 tsp. basil
1 med. onion, chopped fine
6 to 8 oz. thin spaghetti, cooked 10 min. and drained
2 (8 oz.) cans tomato sauce
1 (4 oz.) can mushroom pieces, drained

Boil pepperoni for 5 minutes to remove excess fat; drain. Saute onions in 1 1/3 tablespoon butter until golden brown. Preheat oven to 350 degrees. Pour remaining 1/4 cup butter into an 11 x 7 x 2 inch baking dish. Toss cooked spaghetti in butter. Cover spaghetti with 1 can of tomato sauce. Add in order listed: one-half of Swiss cheese, one-half of the pepperoni, one-half of the Mozzarella cheese, and all of the mushrooms and onions. Sprinkle with the oregano and basil. Add other can of tomato sauce. Top with remaining Swiss cheese, pepperoni, and finally the Mozzarella cheese. Bake 20 to 25 minutes at 350 degrees.