Herring Sauce
Chop a few herring fine, add to it some soup stock, a spoonful of flour browned in hot fat, also an onion chopped very fine. (The herring should be washed in cold water before adding to the stock.) Place on the fire to boil a few minutes, then add a little vinegar and sugar; strain the sauce through a fine sieve and add a few capers and one wineglass of white wine. When it comes to a boil, thicken with the yolk of two eggs.