Skin, clean, and cut off the horribly homely heads. Sprinkle with salt,
to remove any muddy taste they may have contracted from the flats or
holes in which they have fed, and let them lie in a cool place for an
hour or so. Then put them into a saucepan, cover with cold water, and
stew very gently for from half to three-quarters of an hour, according
to their size. Add a chopped shallot or button-onion, a bunch of
chopped parsley, a little pepper, a large tablespoonful of butter, a
tablespoonful of flour mixed to a paste with cold water; boil up once,
take out the fish carefully, and lay in a deep dish. Boil up the gravy
once more, and pour over the fish. Send to table in a covered dish.