Preheat a griddle or a large non-stick pan over medium heat.

Take 4 slices of bread and place 1 slice of Muenster cheese on each of them.

Cover the cheese with the remaining slices of bread.

Spread a tablespoon of butter on each side of the sandwiches.

Place the sandwiches on the griddle or pan and cook for 3-4 minutes on each side or until the bread is golden brown and the cheese is melted.

Remove from heat and serve hot.