4 tablespoons extra-virgin olive oil |
3/4 cup finely diced red onion |
1/2 pound bacon, 1/4 inch diced |
1/2 cup balsamic vinegar |
3 heads romaine lettuce, cut in half lengthwise |
1/2 cup crumbled blue cheese |
freshly cracked black pepper |
preheat a grill or indoor grill pan to high. |