Step 1

To make the dressing, in a medium bowl, whisk together buttermilk, mayonnaise, sour cream, red onion, dill, parsley, garlic, lemon juice, sugar, and salt and pepper to taste (I like 1/2 teaspoon salt and 1/4 teaspoon pepper). Refrigerate at least 10 minutes to blend flavors. Whisk to recombine before serving.

Step 2

On a large platter or in a shallow bowl, make a bed of lettuce. Working with one ingredient at a time, arrange in rows the chicken, blue cheese, egg, tomatoes, bacon, and avocado. Sprinkle with chives and serve with dressing.