Whisk together the mayonnaise, buttermilk, vinegar, scallions, parsley, chives, thyme, 1/2 teaspoon salt and 1/4 teaspoon pepper in a medium bowl. Cover and refrigerate until ready to use.
Cook’s Note
Freshly ground black pepper is an important seasoning. Instead of buying ground black pepper, I use a pepper mill and grind it myself. You can really taste the difference.