Method
Place the butter in a pan to melt. Add a few shallots or onion with a few cloves of garlic, to taste. Heat through for a minute, stirring, then cover and transfer it to the simmering oven. Allow it all to soften for 20 minutes before returning to the pan to the boiling plate.
 
Wash and pick over the mussels, discarding any that have broken shells, or are noticeably heavy - these are likely to be full of mud. Any that are open should close when tapped, indicating they’re alive and fresh. 

Scrape off any barnacles with the back of a sharp knife and remove any pieces of beard.

Add the white wine to the pan, followed by the prepared mussels. Replace the lid and cook for 2-3 minutes, no longer or they will go rubbery.

The mussels should have opened up, now transfer to the serving dish

The mussels juices will have made their own fish stock. Add a generous amount of black pepper to the fish stock, you can use double cream, crème fraîche or in fact leave it out if you prefer.

Add fresh parsley and boil for a couple of minutes so the stock reduces slightly to give a sauce consistency that’ll coat the cooked mussels. Pour the delicious sauce over the mussels and serve with crusty white bread.

Variations
For another classic French version, use cider to give a Normandy finish.

For an Asian version include chilli flakes, galangal and a little bit of fresh ginger.

Hints & Tips
Mussels are available from September through until April.