01 - Whisk together sour cream, mayonnaise, and buttermilk in a medium bowl until smooth.
02 - Stir in parsley, dill, chives, garlic, lemon juice, Dijon mustard, salt, and pepper.
03 - Mix thoroughly to combine all ingredients. Taste and adjust seasoning if necessary.
04 - Cover and refrigerate for at least 30 minutes to allow flavors to meld.