Fry bacon in skillet

Sautee onion slice in left over bacon grease until onion is caramelized

Set onion and bacon to side.

Melt butter in microwave.

Apply melted butter to one side of each piece of bread.

Put small skillet on oven range set on medium heat.

Place one piece of bread butter side down in skillet. Then place slice of mozzarella cheese on bread, then bacon on top of slice of mozzarella, then layer the american cheese on top of bacon, onions on top of american cheese and then the slice of provolone cheese on top of the onions. Put other slice of bread on top of everything with the butter side on top.

Brown each side of sandwich and cook until all of the cheese is melted all the way through.