Barefoot Contessa (en-US)

1 cup good mayonnaise, such as Hellmann’s
2 tablespoons buttermilk, shaken
1 teaspoon good white wine vinegar
2 tablespoons thinly sliced scallions, white and green parts
1 tablespoon minced fresh parsley
1 tablespoon minced fresh chives
¹⁄8 teaspoon minced fresh thyme leaves
Kosher salt and freshly ground black pepper

Whisk together the mayonnaise, buttermilk, vinegar, scallions, parsley, chives, thyme, ½ teaspoon salt, and ¼ teaspoon pepper in a medium bowl. Cover and refrigerate until ready to use.

Buttermilk Herb Mayo