Directions

1. In a heavy 3-to 4-quart stockpot, heat oil over medium-high heat. Add the leeks and a pinch of salt. With a wooden spoon, turn the leeks over in the oil a few times. Reduce the heat to low, add the ginger and garlic, cover, and cook gently for 15 minutes.
2. Make a bouquet garni by tying together with kitchen twine or wrapping in cheesecloth the celery leaves, sage, cinnamon stick, and cloves.
3. Add the bouquet garni to the pot. Then add the squash, apple cider, and the stock. Raise the heat, and bring the soup to a boil. Reduce the heat to as low as possible, and simmer, covered, for 30 to 40 minutes, until the squash crushes easily against the side of the pot when pressed with a wooden spoon.
4. Remove the bouquet garni, and pass the soup through a food mill or puree using an immersion blender. Season with pepper. Swirl in butter if using.
5. Serve the soup garnished with a pinch of cinnamon and a sprinkle of parsley.