In a large saucepan, add the butter and melt. Add the leeks and shallots and sweat for 3 minutes, or until softened. Add the white wine and reduce by 1/2, about 4 minutes. Add the cream and reduce by 1/4, about 3 more minutes. Add the mussels, cover, and cook until the mussels open, about 5 minutes. Discard any unopened mussels. Sprinkle with chives and remove from the heat. Serve in bowls with the French bread.
Recipe courtesy of Emeril Lagasse, 2003