Carefully wash the mussels, passing them multiple times under running water to remove any dirt and impurities.
Place a saute pan over medium heat with 1 tbsp oil.
When hot, add 1 clove of peeled garlic.
When the garlic becomes golden, add the mussels.
Cover and cook until open, then remove from the heat and let cool.
In the meantime, collect parsley, remaining garlic finely chopped, breadcrumbs, salt and remaining oil in a bowl. Mix with a wooden spoon until smooth.
Once the mussels are cool, open them and separate the empty half shells from the ones with the mussels.
Place the half shells with the mussels on a baking sheet lined with parchment paper. Fill the shells with the breadcrumb mixture. Bake in a 400° F oven for a couple of minutes or until the mussels are golden.
Serve either warm of cold, with a squirt of lemon juice if you like.