To begin, set the oven temperature to 200 degrees Celsius. Take a head of garlic and trim off the pointy end. Place the exposed end facing up on a sheet of foil. Next, drizzle as mall amount of olive oil over the garlic and add a pinch of salt and pepper for flavor. Wrap the foil around the garlic and place it in the oven to bake for an hour. Once finished, remove the garlic and let it cool before further use.
In case the mussels are fresh, rinse them and steam them until they open up. Dispose of the ones that don't open. Let them cool. If frozen mussels are being used, thaw them in the fridge overnight before using. When using fresh mussels, eliminate half of the shell. Eliminate the beard if there is one.
Extract the garlic cloves from the head and place them into a bowl. Combine the garlic with butter, lemon juice, and parsley. Arrange the mussels on a baking tray.
Spoon one teaspoon of the garlic butter onto every mussel.
Cook the grill under the broiler for approximately 10 minutes, or until it shows signs of browning. Then, decorate it with garnish and serve it.