Trim the fillets, lay them in a frying pan and cover with the cream. Add the sherry, salt, and pepper, and cook 5 or 6 minutes on the top of the stove. Remove to a baking dish and add the shrimp or lobster and bake in a 400 degrees F oven until the cream and sherry are thick. Add the breadcrumbs and place under the broiler until bubbly and lightly browned. Garnish and serve.