Soak the mussels in cold water, carefully clean the shells, removing all mussels whose shells are open.
Add the mussels to this mixture, cover with a lid and saute 2-3 min., shaking the container periodically.
Take out the mussels and remove the shells, filter the sauce through a cheesecloth and sprinkle with black pepper.
Serve a toasted slice of bread covered with mussels and generously soaked in sauce. Before serving, sprinkle with parsley.