This is pretty much a dead ringer for Hidden Valley Original Ranch Salad Dressing®, but without the Calcium Stearate, Monosodium Glutamate, Disodium Inosinate, Disodium Guanylate, Carboxymethylcellulose, Guar Gum or other unpronounceable ingredients.
Place mayonnaise and buttermilk in a bowl and whisk well until completely smooth and free of lumps.
Add the rest of the ingredients. Continue whisking until well combined and so beautiful you feel yourself wanting to dive in.
Cover and place in the refrigerator to allow the flavors to mingle and become fully acquainted. Store tightly covered in refrigerator.
Notes
To make one cup buttermilk substitute: Pour 1 tablespoon white vinegar into a glass measuring cup. Add milk up to the one-cup line and stir. Place cup in the microwave on 50% power for 45 - 60 seconds. Stir and use in place of one cup of buttermilk.