
Mash the garlic and salt into a paste with the side of a chef's knife. In a medium bowl, whisk together the garlic paste, mayonnaise, 1/4 cup buttermilk, chives, parsley, vinegar, scallions and pepper to taste. If the sauce is very thick, thin the dressing with a couple tablespoons more of the buttermilk. Use immediately or store covered, in the refrigerator, for up to 3 days.