Chestnuts roasting on sidewalk carts are quintessential New York this time of year: If Woody Allen movies had aroma tracks as well as sound tracks, the autumn scenes would be infused with their fragrant, nutty smoke. Thanksgiving is a perfect time to feature this starchy seasonal nut in stuffing, Brussels sprouts, or sautéed with green beans.

New York chefs will be preparing some mouth-watering variations for the big meal next week. At Payard Bistro (1032 Lexington Ave., 212-717-5252), the chestnut plays a supporting role in mushroom and chestnut risotto with sage and has a cameo in foie gras-chestnut stuffing. But chestnut is the star in chestnut soup. The chef at Orsay, Jason Hicks, makes his version with Granny Smith apples and sage (1057 Lexington Ave., 212-517-6400) and chef Kurt Gutenbrunner offers chestnut soup flavored with mushroom broth and with Armagnac-soaked prunes at Wallsé (344 W. 11th St., 212-352-2300).

Like most good things, you have to work to get to the good part: past the thin, sharp mahogany shell, then to the fuzzy undercoat, until finally you reach the wrinkly “brain.” Some recipes suggest that bottled or canned chestnuts are a satisfactory substitute for fresh. But when you roast your own, there’s a bright freshness and firm texture that you can’t get from already cooked chestnuts. Even the best pre-cooked chestnuts tend to be softer and sweeter than fresh, and a little bit mealy. For a special occasion like Thanksgiving, there’s an intense satisfaction that you get from roasting your own.

Kurt Gutenbrunner’s Chestnut Soup Viennese Mélange

1. Mix 1/2 cup of water and 1/2 cup of Armagnac or Cognac in a saucepan. Add 8 whole, pitted prunes, bring to a simmer, remove from heat, cover, and let steep 6 hours or overnight. Reserve.

2. Wash 12 oz. of button mushrooms, cover with water in a saucepan and simmer for one hour. Strain, discard mushrooms, and reserve juice in the refrigerator.

3. Pulverize 2 dried porcini mushrooms in a blender or coffee grinder and reserve.

4. Preheat oven to 375 degrees. Score 1 lb. of chestnuts. Roast in a single layer on middle level of the oven for 10 to 12 minutes, or until the shell skin curls. Let rest until cool enough to handle, remove the shells, and reserve the nuts.

5. Melt 4 Tbsp. butter over low heat. Add 1 medium celery root (diced), and sweat for 5 min. Add peeled chestnuts, seasoning with salt and pepper. Stir in 1 Tbsp. sugar, raise the heat, and cook a few minutes, until caramelized. Add 1/4 cup of Armagnac or Cognac, and cook for a minute. Add the reserved 1 cup mushroom juice and 4 cups chicken stock, lower heat, and cook slowly for 15 minutes. Add 1 cup heavy cream, and cook for another 5 minutes.

6. Remove from the heat, let cool for about 5 minutes, and transfer to a food processor or blender. Carefully blend, working in batches if necessary. Strain and reseason. (The soup can be made up to this point a day in advance, covered and refrigerated).

7. To serve, place one drained prune in each of 8 soup bowls or cups. Put 2 cups skim milk in a tall, slender container, and add 1/4 tsp. ground porcini and 1/8 tsp. nutmeg. Using an espresso machine or other foaming device, foam the hot milk.

8. Pour equal amounts of the soup into the soup bowls, top with a scoop of foam, a shaving of optional black truffle, and a parsley leaf. Serve immediately.

Serves eight.