1.75 kg mussels, cleaned
50 g unsalted butter
1 medium onion, finely chopped
50 ml dry white wine
1 tablespoon coarsely chopped parsley
Crusty white bread, to serve
Put the mussels, butter, onion and white wine into a very large pan. Cover and cook over a high heat for 3–4 minutes, shaking the pan every now and then, until the mussels have opened.
Spoon the mussels into 1 large or 4 individual warmed bowls. Add the parsley to the remaining juices, then pour all but the last tablespoon or two, which might contain some grit, back over the mussels. Serve with plenty of crusty white bread.