Boil mussels in water until it opens. Remove from heat, drain the water and discard closed shells.

While waiting for the shells to cool, prepare the garlic butter topping. Combine the two ingredients and mix well. In a separate bowl, grate the quick-melt cheese..

Once shells cooled, lay out halved shells on a baking tray. Top each with a generous serving of the garlic-butter mix.

Add the grated cheese on top of each.

Bake in a preheated oven until the cheese melts (low setting since the mussels already cooked when you boiled then).

Once the cheese melts, remove from the oven and serve.