Remove the core of the lettuce by pounding the lettuce on the counter top one time, core side down. This will loosen up the core and you should be able to remove it by hand. 

Now cut the head of lettuce in half, then cut each piece in half one more time. Place the individual lettuce wedges on a  large tray lined with parchment paper. 

Now sprinkle your thinly sliced onions, tomatoes, blue cheese crumbles, and bacon pieces over the top of each wedge of lettuce. 

Add your black pepper evenly over each lettuce wedge. Drizzle the blue cheese dressing and vinaigrette dressing over the top of the salad; or place it on the side for serving. 

Serve immediately.