Purée of Chestnut Soup

Ingredients

2 tbs. unsalted butter
2 tbs. extra-virgin olive oil
1 large yellow onion, finely diced
2 tsp. freshly chopped rosemary
6 cups homemade chicken stock (canned broth can be substituted)
5 cups fresh peeled chestnuts (available frozen at Buon Italia, Chelsea Market; 212-633-9090)
1 cup heavy cream
Salt

Garnish
Cracked black pepper
Crème fraîche
Chives
Pan-roasted chestnuts (a handful)

Instructions

In a heavy saucepan, melt the butter and oil, and add the onion, rosemary, and a pinch of salt. Cook gently over medium heat for about 5 minutes until the onion is translucent. Add the chicken stock and chestnuts, bring to a simmer, and cook gently for about 30 minutes until the chestnuts are tender. Purée the soup in a blender until smooth. Add the cream, and simmer gently for 10 minutes, allowing the cream to blend into the mixture. Season to taste with salt, garnish, and serve hot.

Note: If using unpeeled ch