Sauce til Kålsalat

Ingredients

 * 1½ tablespoons butter
 * 1 tablespoon flour
 * 1 tablespoon sugar
 * ½ teaspoon dry mustard
 * ½ teaspoon salt
 * 2 tablespoons white vinegar
 * 2 tablespoons water -- mixed with
 * 1 egg -- beaten

Directions
Combine all ingredients and cook over low heat until mixture begins to thicken slightly. Cool. If too thick, add enough cream to thin to desired consistency.