In a medium bowl stir together the sour cream, mayonnaise, ¼ of the blue cheese, buttermilk, lemon juice, salt, and pepper. Stir well until smooth. Gently stir in the remaining ¼ cup crumbled blue cheese. Refrigerate for at least 20 minutes before serving. At this point you can store it in the refrigerator up to 3 days.
Remove any limp outer leaves of the iceberg salad and then cut in half, then cut each half into quartered wedges.
Place each wedge on a plate and drizzle with the blue cheese dressing. Top it with a few crumbles of bacon, sprinkle of chives (if using), reserved blue cheese chunks and the tomatoes.
Give one or two more sprinkle of freshly ground pepper and serve.
Giangi's Kitchen provides nutritional information, but these figures should be considered estimates, as a registered dietician does not calculate them.