Leeks are the king of onions and provide a hearty depth to a recipe. This recipe for Gratin of Leeks, Bacon and Cheddar is just want you want for a decadent bowl of goodness. It takes 50 minutes to prepare this dish that taste great as a dip with your favorite vegetables, chips, or bread. This super rich and decadent recipe combines salty bacon with creamy cheese for a gratin that will melt in your mouth.