01 - In a medium mixing bowl, add the sour cream, mayonnaise, prepared horseradish, Dijon mustard, white wine vinegar or lemon juice, salt, and ground black pepper.
02 - Stir all ingredients thoroughly using a whisk or spoon until the mixture is completely smooth and evenly combined.
03 - Taste the sauce and adjust the horseradish quantity or additional seasoning to suit your preferred heat level.
04 - For a brighter, fresher flavor, gently fold in chopped fresh chives or parsley.
05 - Cover the bowl tightly and refrigerate for at least 30 minutes to allow the flavors to develop and meld together.
06 - Serve chilled alongside roast beef, smoked fish, grilled vegetables, or your favorite sandwiches.