Roughly chop the bacon into small pieces and cook in a skillet over medium low heat, turning and stirring now and then to ensure the bacon cooks evenly and doesn’t burn.
Meanwhile, measure vinegar and maple syrup in a small saucepan and bring just to a simmer. Allow the glaze to cook while the bacon cooks. The glaze is done when it coats the back of a spoon. Remove from the heat and set aside.
Meanwhile, prepare your lettuce. Remove the outer leaf and cut out the core. Cut into 4 wedges, cutting each wedge in half. Divide between four dinner plates.
Slice the red onion thinly, or dice it.
Top the wedges evenly with red onion, chopped walnuts, cheese and dried cranberries.
When the bacon is done, remove with a slotted spoon and top the salads.