Place the cheddar and mozzarella cheese between the two pieces of bread.
Butter the outside of both pieces of bread.
Mix the pecorino romano and parmesan cheeses together in a shallow dish.
Press the buttered sandwich on the mixed shredded cheeses to make a cheese crust.
In a pan or on a griddle place the sandwich on medium heat for 2 minutes per side.
Keep flipping the sandwich until the cheese melts on the inside and the cheese on the outside makes a beautiful crust.