Melt the butter in a large saucepan, add the shallots and garlic and cook for 3–4 minutes until softened. Pour in the wine and bring to the boil.
Add the mussels (first discarding any that don't shut when tapped against a work surface), cover the pan and cook for 3–4 minutes, shaking the pan once or twice, until all the shells are open. Discard any mussels that remain shut.
Stir in the cream and parsley and heat through.
Serve in deep bowls with crusty bread to mop up the juices.