Brown 1 pound hamburger or 1 pound turkey hamburger and 1 small onion chopped. Mix 1 (32 ounce) jar Ragu sauce into this, then put on top of first mixture. Put 3 to 4 cups of shredded Mozzarella cheese on top of hamburger then 3 1/2 ounce package of sliced pepperoni on top. Put aluminum foil on top and bake 30 minutes in 350 degree oven. Take foil off and bake another 20 minutes. Let stand 10 minutes before cutting.