Vegetable Sauce
["1/2 stick butter or margarine", "1 1/2 c. mayonnaise", "2 Tbsp. horseradish", "1 small onion, minced", "1/2 tsp. dry mustard", "1/2 tsp. salt", "1/4 tsp. cayenne pepper", "2 tsp. tarragon vinegar"]
["Place all ingredients in a heavy glass jar.", "Set in a pan of hot water and turn the heat on low.", "Stir until well blended and heated through.", "Refrigerate; reheat and use as needed.", "Serves 8 to 10."]
["butter", "mayonnaise", "horseradish", "onion", "dry mustard", "salt", "cayenne pepper", "tarragon vinegar"]