Place all ingredients into a large heavy-bottomed pan or Dutch oven. Ensure there’s enough liquid to cover – top with more water if necessary.
Bring to a boil uncovered on the stove, skimming any scum off the top. After 30 minutes, cover and place into oven. Cook for 5 hours.
Once cooled, strain the soup. Discard the celery. Shred the chicken breast and cut the carrots into thick slices, then add back into the soup. Either add the leeks and rutabaga back into the soup or squeeze them through a fine strainer to release their juice, then discard the remaining pulp.
If you refrigerate the soup overnight, the fat will solidify on top, which makes it easy to remove – if you choose to. I usually do, then use it to make matzah balls.