Melt butter in large skillet and saute' onion and mushrooms until soft. Remove with slotted spoon and reserve. Saute' livers in same skillet until lightly browned, adding more butter if necessary. Add wine and heat to boiling. Stir in cream, mustard, salt and pepper, sugar and parsley. Blend well. Simmer until livers are no longer pink and sauce is thickened. Return mushroom and onion mixture to livers just long enough to reheat. Serve at once. Serves 6 to 8. SOURCE: *Quick Italian Cuisine International, Knapp Press C 1984 ISBN 0-89535-147-1 SHARED BY: Jim Bodle 0.032258064516129