01 -
Start heating your pan on medium-low. Grab a slice of bread, smear butter on one side, then put it down on your counter with the buttered side facing down.
02 -
Add your fillings in this order - grated cheese, prosciutto slices, chunks of fresh mozzarella, basil, and a dollop of pesto. Sprinkle with salt and pepper, then cap with your second bread slice. Butter the top side that's facing up.
03 -
Drop your sandwich into the warm pan and let it cook gently for around 5 minutes per side. You want a nice crunchy golden outside and melted, gooey cheese inside.