Mussels a la Mariniere

The mussels should be prepared as for No. 1045. Cook in butter one shallot with the same quantity of very finely chopped onions; moisten with white wine, add the mussels and a little veloute sauce (No. 415), and mussel broth; keep this warm and just when ready to serve, stir in a piece of fresh butter and chopped parsley.