For the dressing: 1/2 cup buttermilk 2 Tbl mayonnaise 2 Tbl sour cream 1/4 cup sliced chives 1/4 cup chopped tarragon 2 Tbl chopped parsley 1/4 tsp dry mustard 1 Tbl cider vinegar 1/4 tsp freshly ground black pepper 1 tsp kosher salt For the root vegetables 2 medium carrots 2 medium parsnips 4-6 radishes 2 medium golden beets 1 small turnip 1 small celery root 1 small rutabaga kosher salt, to taste freshly ground black pepper, to taste
For the dressing: Combine all the ingredients in a medium-sized mixing bowl, and stir to combine. Refrigerate in an air-tight container until needed, up to a day.
For the root vegetables: Wash all of the root vegetables in cool running water. Peel the carrots, parsnips, celery root and rutabaga, but leave the skins on the radishes, beets and turnip. Using a mandolin, slice the root vegetables into paper-thin circular slices. Add the slices to a large mixing bowl and cover with cold water. Refrigerate covered, until ready to serve.
To assemble: Dry the sliced root vegetables very thoroughly in a salad spinner. (Give this step about twice as much time as you think it needs – it’s important that they are very dry, so the dressing will stick.) When no more water is released from the salad spinner, pat the sliced vegetables with paper towels, to pick up any lingering water. Place the sliced vegetables into a large, dry mixing bowl and top with the dressing. Season with salt and pepper. Stir with a rubber spatula, evenly coating each slice with the dressing. Arrange a small cluster of dressed root vegetable slices in the center of each salad plate. Sprinkle with a pinch of salt and a small grind of pepper.