Position the oven rack in the center. Preheat to 375°F (191°C).
Line a large sheet tray with foil and place bacon on the pan making sure not to overlap.
Roast the bacon for 15 minutes. Remove the tray from the oven and use tongs to flip over.
Bake until bacon is fully cooked, about 3 to 5 minutes.
Transfer bacon to a paper towel-lined sheet tray to absorb the excess grease. Once cool, chop into small pieces.
In a medium bowl whisk together sour cream, mayonnaise, whole milk, blue cheese, lemon juice, garlic powder, salt, and pepper. Break up the blue cheese crumbles as needed, the dressing will be smooth with some chunkier pieces.
Cut a head of iceberg lettuce through the core. Cut the halves down the center, there should be four wedges. Remove any outer leaves that are browned or falling off.
Gently rinse the lettuce wedges under cool water for a few seconds. Carefully shake off the excess water and dry with paper towels.
For super cool and crisp wedges, refrigerate before serving.
Divide the wedges amongst serving plates. Drizzle with blue cheese dressing then top with bacon, red onion, tomatoes, chives, crumbled blue cheese and black pepper.
For stovetop bacon: Add bacon strips to a cold pan. Turn heat to medium-low and cook until it starts to curl and turn deep red in color, about 12 minutes. Flip about every 4 minutes.