Soak six medium-sized salt mackerel, with flesh side down, in plenty of cold water forty-eight hours, changing water several times. Drain and wipe dry. Broil about twelve minutes, or until browned slightly. Remove to hot platters, spread with prepared butter, and garnish with parsley and slices of lemon or cucumber pickle.

For the butter, cream one cup margarine and one tablespoon vinegar or lemon juice, using the acid that corresponds with garnish. If lemon is used, add grated rind.