Preheat oven to 375˚F.
Lightly grease a baking dish with a pat of butter.
Season chicken breasts with salt and pepper; arrange the chicken in a single layer in the prepared baking dish and set aside.
Add butter to a skillet and melt over medium heat.
Stir in the garlic and cook over medium heat for 4 to 5 minutes, or until lightly browned, stirring very frequently. DO NOT burn the garlic.
Stir in the rosemary and remove from heat.
Pour the prepared garlic butter over the chicken breasts.
Bake for 30 to 32 minutes, or until the chicken's internal temperature registers at 165˚F.
Sprinkle with cheese and cook for an additional 3 minutes, or until cheese is melted.
Remove from oven and let stand for about 5 minutes.
Transfer the chicken to serving plates; spoon garlic butter sauce over the chicken and serve.