In a medium side bowl, mix together the mayo, sour cream, mustard, salt and pepper.
In a food processor or blender, add the chopped garlic, chopped chives, chopped green onion, distilled vinegar, balsamic vinegar and fresh squeezed lime juice.
Pulse or blend this mixture until the herbs and garlic start to break down. Add the buttermilk and blend until the herbs and garlic break down but are still noticeable. Don't blend until completely smooth - some chunks are good here.
Add the blended herb mixture to the mayo mixture and stir well. Add more salt and pepper to taste if desired.
Store the in the fridge overnight to let the flavors develop, if desired.
This dressing will last 7 days stored in the fridge.