BOILED MACKEREL—IV
Clean a fresh mackerel and split it down the back. Put it in a dripping-pan and pour over it two cupfuls of boiling water, two tablespoonfuls each of vinegar and lemon-juice, and a teaspoonful of salt. Add a sliced onion and boil for three quarters of an hour. Take up the fish, strain the liquid, add a teaspoonful of capers, bring to the boil, and pour over the fish.