This very plain fish soup is most popular in Norway. It is generally made with coal-fish, which is very abundant in the waters around Norway. This fish, which is sometimes called green cod or black pollock, has a wide range, nearly coinciding with that of cod, although it is occasionally found in the Mediterranean.
For 6 people, take 5 lbs. of small coal-fish, about 10 to 15 inches in length, clean thoroughly, and cut into large pieces. Put them in a saucepan with 2½ quarts of salted water, bring to the boil and simmer for 2½ to 3 hours. Strain the stock, thicken with a white roux, made with 1 tablespoon of butter and 1 of flour, and flavour with Marsala wine. This same soup is sometimes served as a brown soup, by browning the flour and butter which are added to it. It is then seasoned with cayenne pepper, and less wine is added.