Mix together the sour cream, buttermilk, garlic, Worcestershire, vinegar, cayenne, salt, and pepper.

Add the fresh herbs.

Stir well. Check for seasoning. I find that it needs a lot of salt and pepper. If the dressing is too thick, thin it with a little more buttermilk.

Put in a jar, and keep in the fridge, it should keep for about a week. It just tastes better and better as it chills.