This soup has a wonderful combination of apples, bacon (I use a bacon substitute) and leeks. Not too sweet, with a nice "bite." Sweet-tart apples and smokey bacon play off one another nicely. Good Fall soup, or Thanksgiving side dish which was when I made it. I could not find celery root so I added a few more stalks of celery. Can be made a day ahead, refrigerated and reheated for the next day. Leftover apple rings make a great snack. From a 2006 issue of Cottage Living, a Sara Foster recipe.