Carefully scrape the mussels and wash them 2 or 3 times. Drain and set aside in a cool place.
Peel and finely chop the shallots.
Chop the parsley, then peel and mince the garlic.
In a large saucepan, melt the butter. Add the shallots and cook for a few minutes, until translucent.
Finally, add the garlic, parsley and mussels. Sprinkle with white wine and season with pepper.
Cover and cook over high heat for 5 minutes, stirring occasionally with a skimmer.
Stop cooking when all the mussels have opened. Discard any unopened mussels.