Step 1

Preheat a non-stick skillet or griddle over medium heat.

Step 2

Butter one side of each slice of sourdough bread with the softened butter. If using mayonnaise, spread it on the opposite side of one slice of bread.

Step 3

Place one slice of bread, buttered side down, onto the skillet.

Step 4

Layer one slice of cheddar cheese, followed by a slice of provolone cheese, and then the slice of mozzarella cheese on the bread in the skillet.

Step 5

Top with the second slice of cheddar cheese and then a slice of provolone cheese.

Step 6

Place the second slice of sourdough bread on top, buttered side up.

Step 7

Cook for 4-5 minutes on one side or until the bread is golden brown and the cheese starts to melt.

Step 8

Carefully flip the sandwich and cook for an additional 4-5 minutes or unIl the other side is golden brown and the cheese is fully melted.

Step 9

Remove from the skillet and let it sit for a minute before slicing.

Step 10

Cut the sandwich in half and serve immediately.