8 oz. pkg. spaghetti, broken into bite-size pieces
1/2 c. onion
1/2 c. butter
1 lb. hamburger meat
1 pkg. pepperoni
16 oz. jar spaghetti sauce
4 oz. Cheddar cheese
4 oz. Mozzarella cheese
4 oz. Swiss cheese

Cook spaghetti according to directions on package. In casserole dish, melt butter with onion. Brown hamburger and drain. Layer the casserole dish with the following: spaghetti, hamburger, spaghetti sauce, Cheddar cheese, Mozzarella and Swiss cheese. Top with pepperoni slices.

Bake at 425°F for 20 minutes.