-
1
Adjust oven rack to middle position and heat oven to 400F
-
2
With a small, sharp knife, slit the outer shell of each chestnut, put them in a shallow baking pan, and roast until tender, 15 to 20 minutes.
-
3
Peel off the outer shells and inner skins while still warm.
-
4
Reheat if the chestnuts cool and become difficult to peel.
-
5
Peel and thinly slice the onion and the shallots.
-
6
Thinly slice the celery tops and leaves (reserve ribs for another use).
-
7
Julienne the prosciutto.
-
8
Wrap and refrigerate 2 tablespoons prosciutto for garnish.
-
9
Heat 2 tablespoons of the butter in an 8-quart soup kettle and saute the onion, shallots and remaining prosciutto over medium heat until softened, about 5 minutes.
-
10
In a large saucepan, bring 6 cups of the chicken stock to a boil.
-
11
Stir the hot chicken stock into the shallot mixture along with the chestnuts, celery, fennel seeds, bay leaf, and 1/2 teaspoon salt.
-
12
Bring the mixture to a boil and skim.
-
13
Reduce the heat and simmer, covered, for 45 minutes.
-
14
Remove and set aside 16 chestnuts for garnish.
-
15
Add optional mushrooms.
-
16
Continue simmering until remaining chestnuts are very tender, about 45 minutes longer.
-
17
Remove soup from heat, discard the bay leaf, and set aside to cool 15 minutes.
-
18
Pour the soup into the workbowl of a food processor fitted with a metal blade, or into a blender.
-
19
Add heavy cream and white pepper while pureeing.
-
20
Strain before serving.
-
21
Reheat and serve hot.
-
22
Can cover and refrigerate up to 3 days, or freeze up to 1 month.
