Meanwhile, prepare Green Goddess Dressing: In blender, puree buttermilk, mayonnaise, Greek yogurt, anchovies or anchovy paste, lemon juice, Dijon mustard, garlic, pinch sugar, salt and pepper until smooth. Add parsley, basil, tarragon and chives; pulse until herbs are finely chopped. Makes about 2 cups; can be refrigerated up to 1 week.