If I could afford it, I would eat this repeatedly every day.

Modifications and Tips
Spice up the butter mixture with diced jalapeños or a pinch of red pepper flakes for an extra kick. If you like your cheeses a little cheesier, you can top the mozzarella with shredded cheddar or Gouda. Herb lovers will find that a little chopped basil or parsley really brings out the best in any dish.