Email to Kathy Gydus Recipe Categories: kathygy's HOME PAGEBEVERAGES CAKESandPIES COOKIES DESSERTS MEATS POULTRY SALADandDRESSING SAUCES SNACKS MUSTARD HORSERADISH CREAM SAUCE. Source of Recipe Unknown Recipe Introduction This goes with my Beef Tenderloin recipe. List of Ingredients 1/3 cup Dijon mustard. 1/3 cup sour cream. 1/4 cup prepared mayonnaise. 1/4 cup well drained prepared white horseradish.Recipe Whisk all the ingredients together in a small bowl. Refrigerate, covered, until ready to use.