Preheat oven to 400°F (205°C).
Place bread slices on a baking sheet.
In a small bowl, mix together melted butter and minced garlic (if using).
Brush the mixture evenly on both sides of the bread slices.
Sprinkle grated cheese evenly on top of each slice.
Bake in the preheated oven for 10 to 12 minutes, or until cheese is melted and bread is golden brown.
Serve hot.