Place the bacon in a medium, heavy skillet over medium heat. Add the bacon and cook, stirring, until it is Cook golden on all sides, which will take about 7 minutes. If you need extra fat, add the oil, so the bacon browns nicely. Transfer the bacon to a plate lined with paper towel. Drain off all but 1 tablespoon of fat from the pan, if necessary. Add the leeks, stir, season lightly with salt and pepper and cook, covered, stirring frequently, until the leeks are tender, which will take 8 to 10 minutes.