Sauce: Put shallots into sauce pan with wine; Boil gently until wine has evaporated; Mix cream and mustard together and add to the shallots; Season with salt and peppier and bring to a boil; Boil over medium heat, stirring often, until mixture thickens (about 8 minutes); Cool.
Preheat oven to 425 O.
Arrange fillets crosswise, overlapping each other by about 1/2 inch in shallow oven-proff dish;.
Melt butter and spoon over fish;.
Spoon lemon juice over fish;.
Pour sauce over fish in a wide band down the center;.
Cook for 10 - 15 minutes, until fork penetrates easily.