Stir together the butter, Worcestershire sauce, lemon juice, pepper, hot sauce, garlic and salt. Pour half this mixture into a large heatproof baking dish. Layer half the prawns or shrimp and half the lemon slices in the dish; form a second layer with the remaining shrimp and lemon slices, pour the remaining sauce into the dish. Bake, uncovered, for 20 minutes or until the prawns or shrimp are pink, stirring twice. Pour off the sauce into individual serving dishes and serve with French bread, optional.