The mussels are grilled with roast garlic and a little butter. Roasted garlic has a subtle sweet taste that complements the mussels rather than overpowers them. To balance the sweetness, the balsamic vinegar adds a little acidity.
Cut the pointy end off the head of garlic and lay exposed end up on a sheet of foil.
Drizzle with a little olive oil and season with a pinch of salt an pepper
Wrap in the foil
Cook in the oven for 1 hour
Remove and allow to cool
If mussels are fresh, wash them then steam them until they open. Discard any that do not open. Allow to cool. If using frozen mussels, allow to thaw in the refrigerator overnight before using.
Remove half the shell if using fresh mussles. Remove the beard if there is one.
Squeeze out the cloves of garlic from the head into a bowl
Add the butter, lemon juice and parsley and combine
Arrange mussels on a baking tray
Add a tsp of the garlic butter to each mussel
Grill under the broiler for 10 minutes, or until starting to brown.
Add garnish and serve. I used balsamic pearls. A drizzle of balsamic vinegar would work.