Preparation

• Prepare a charcoal or gas grill fire for direct grilling over medium heat (350°F).
• Put enough water in a 10-inch skillet to just cover the bottom (about 1/4 cup) and add the bacon in a single layer. Cook over medium heat until the water evaporates and the bacon starts to sizzle, about 2 minutes. Reduce the heat to medium low and cook, stirring occasionally, until the bacon is golden outside and tender inside, about 20 minutes. (You want it to be chewy rather than hard and crisp.) Using a slotted spoon, transfer the bacon to a plate lined with a paper towel to drain. Set aside.

• In a small bowl, mash the blue cheese with a fork. Add the buttermilk, sour cream, and lemon juice and whisk to combine. Season with 1 tsp. salt and several grinds of pepper. Stir in the chives.
• Put the iceberg on a baking sheet, drizzle with the olive oil, toss gently to coat evenly, and season with salt. Place the iceberg on the grill cut side down and grill until nicely marked, 1-1/2 to 2 minutes. Turn and mark on the other cut sides, about 2 minutes more.
• Transfer the grilled iceberg to a platter or individual plates. Spoon a generous amount of the dressing on top, then scatter with the bacon and tomato. Serve immediately, passing any remaining dressing at the table.