To 1½ lbs gray or yellow [powdered] mustard, add ½ lb sugar, 4 tablespoons pounded and sieved rye rusks, 1 dessertspoon salt, ½ teaspoon ground pepper, a small jar each capers and olives, 2 Dutch herring,* and 4 tablespoons herring brine—without the slightest odor. Chop the herring, capers, and olives very fine and rub through a fine sieve. Mix with the mustard and the other ingredients and beat thoroughly, diluting with ½ bottle French vinegar. Then add enough of the best wine vinegar so that the mustard will not be too thick, because it will thicken with time. If yellow mustard is used, pepper need not be added.