Chestnut, Celery Root & Apple Soup with Sage Oil

Makes 6 to 8 servings

2 tablespoons extra-virgin olive oil

1 medium onion, peeled, trimmed and thinly sliced

1 medium leek, white part only, thinly sliced, washed and dried

2 McIntosh apples, peeled, cored and cut into 1/2-inch cubes

10 ounces celery root, peeled and cut into 1/2-inch cubes

1 bay leaf

1 sprig thyme

Pinch of freshly grated nutmeg

Salt and freshly ground white pepper

3/4 pound peeled fresh chestnuts (from about 1 1/4 pounds chestnuts in the shell) or dry-packed bottled or vacuum-sealed peeled chestnuts

2 quarts chicken stock 

1/2 cup heavy cream

8-12 fried sage leaves

2-4 tablespoons sage oil

Heat the oil in a stockpot or large casserole over medium heat.  Add the onion, leek, apples, celery root, bay leaf, thyme, nutmeg and salt and pepper to taste and cook, stirring occasionally, for about 10 minutes, or until the onions and leeks are soft but not colored.  Add the chestnuts and chicken stock and bring to the boil.  Lower the heat to a simmer and cook, skimming the surface regularly, for 35 to 40 minutes, or until the chestnuts can be mashed easily with a fork.  Add the heavy cream and simmer for 5 to 10 minutes more, then remove from the heat and discard the bay leaf and thyme.

Puree the soup until smooth using a blender or a food processor, and working in batches if necessary, then pass it through a fine-mesh strainer.  You should have about 2 quarts soup.  If you have more, or if you think the soup is too thin -- it should have the consistency of a veloute or light cream soup - simmer it over medium heat until slightly thickened.  Taste and, if necessary, adjust the seasoning.  (The soup can be cooled completely and stored in a covered container in the refrigerator for 3 to 4 days or frozen for up to one month.  Bring the soup to a boil before serving.)

Serve topped with a couple of fried sage leaves and a drizzle of sage oil.