Preheat a grill or grill pan over medium-high heat until hot, about 15 minutes.
Cook the bacon in a skillet over medium heat until crisp, about 8 minutes. Transfer the bacon to a paper-towel-lined plate, reserving the fat in the pan.
Meanwhile, stir together the blue cheese, mayonnaise, sour cream, lemon juice, 1/4 teaspoon salt and a couple turns of pepper in a small bowl.
Brush the romaine hearts with the reserved bacon fat and grill until just charred on both sides, about 2 minutes. Serve the grilled lettuce drizzled with the dressing and sprinkled with the bacon.
Copyright 2016 Television Food Network, G.P. All rights reserved.