Boiled Marinaded Mackerel

Put enough weak broth in a fishkettle fitted with a drainer to cover a dozen
mackerel, add three small onions, a bunch of sweet herbs, half a teacupful of vinegar,
eight cloves with pepper and salt to taste, boil all together for one hour ; then put
them in the fish and cook. When it is done take the fish out carefully on the drainer,
being careful not to break them and put one by one on a hot dish. Strain the liquor
in which they were cooked, put in some parsley and hard boiled eggs to thicken it,
mix in some white gravy sauce, turn it into a sauceboat and serve with the fish.