To make the dressing, combine the mayonnaise, sour cream, buttermilk, garlic, 1 tablespoon of chives, 1 tablespoon of tarragon and 3 tablespoons of lemon juice. Add a pinch of salt and pepper to taste. I like this dressing on the more sour side and with lots of herbs so add more lemon juice and minced herbs to taste. Refrigerate to allow the flavors to meld together and the dressing to thicken.