Heat a frying pan or griddle over medium heat.

Spread butter on one side of each slice of bread.

Place one slice of bread, buttered side down, on the frying pan.

Place cheese on top of the bread.

Place the other slice of bread, buttered side up, on top of the cheese.

Cook until the bread is golden brown and the cheese is melted, about 2-3 minutes per side.

Cut the sandwich in half and serve immediately.