Although these delicate fish rolls are part of this dinner party menu as an appetizer cut into one-inch pieces, they also make a lovely light main dish served as is.
Preheat oven to 400 degrees F. Place fillets, skinned-side up, on a flat surface. Combine the bread and cracker crumbs with parsley, 3 tablespoons melted butter, and 1 tablespoon sherry. Toss gently. Center equal portions of the filling on top of the fillets and spread evenly, leaving a slight margin on all sides. Roll up each fillet and secure with a long toothpick or skewer. Put the remaining 3 tablespoons of the butter and 1 tablespoon of the sherry in a shallow baking dish and place in oven for several minutes until hot. Place fish rolls in the baking dish and baste with butter-sherry sauce. Bake for 15 minutes, turning once with tongs. If difficult to manipulate, skip the turning (it’s not absolutely necessary). To serve as an appetizer, slice into 1-inch pieces and serve on a leaf of romaine lettuce with a wedge of lemon.