Haddock Sauce for Crumbed and Baked Haddock.
Put on in cold water, heads, tails, &c., of the fish, with onion, parsley, and peppercorns, to boil ½ hour.
Make the stock for the sauce, thickened with a brown roux and flavoured with anchovy, which gives the fish a flavour of red mullet (“sea woodcock”).
Failing the anchovy you must use mushroom catsup or Harvey's sauce.
Some add a glass of wine.