GUT your mackerel, and slit them down the belly; cut off their heads, take out the bones, and be careful not to cut them in holes. Then lay them flat upon their backs, season them with mace, nutmeg, pepper, and salt, and a handful of parsley shred fine; strew it over them, roll them tight, and tie them well separately in cloths. Boil them gently twenty minutes in vinegar, salt, and water; then take them out, put them into a pot, and pour the liquor on them, or the cloth will stick to the fish. Take the cloth off the fish the next day, put a little more vinegar to the pickle, and keep them for use. When you send them to table, garnish with fennel and parsley, and put some of the liquor under them.