Sweet Potato and Chestnut Soup
Why amplify sweet potatoes’ natural sweetness by adding sugar, as so many recipes do? I’d rather emphasize their nuttiness by pairing them with chestnuts in a silky soup. Look for dry-fleshed Japanese-type sweet potatoes, the kind that are pale gold inside. Serve this soup for dinner with a salad, or in small portions as a first course. For Thanksgiving, you could serve it in espresso cups so guests still had plenty of appetite for the meal to come. Adapted from Fresh from the Farmers’ Market.
- 3/4 pound fresh chestnuts or 18 whole bottled chestnuts, roasted, peeled and dry-packed (about 6 ounces)
- 3 tablespoons unsalted butter
- 1 large yellow onion, minced
- 1 pound dry-fleshed sweet potatoes (see introduction), peeled, in 1/2-inch dice
- 1 teaspoon minced fresh thyme
- Kosher or sea salt and freshly ground black pepper
- Approximately 2-1/2 cups chicken broth, homemade or canned low-sodium
- 1/2 cup heavy cream
- 2 tablespoons crème fraîche, optional
- 2 tablespoons chopped chives, optional
If using fresh chestnuts: Cut an “X” in the flat side of each chestnut, then boil the chestnuts for 10 minutes. With a slotted spoon, lift them out of the hot water one at a time. (They are easier to peel when hot.) Cradle them in a dishtowel if necessary to protect your hands, then squeeze them gently and peel back from the “X,” removing the hard shell and the papery brown skin. The nuts may crumble, but that’s OK. Coarsely chop any large pieces.
If using bottled chestnuts, inspect them and remove any skin still clinging to them. Chop them coarsely.
Melt the butter in a large pot over moderately low heat. Add the onion and saute until soft and sweet, about 10 minutes. Add the sweet potatoes, chestnuts and thyme. Season with salt and pepper. Cook, stirring occasionally, for about 5 minutes, then add 2 cups chicken broth and 2 cups water. Cover, adjust the heat to maintain a simmer and cook until the chestnuts and sweet potatoes are tender, about 15 minutes.
Pass the mixture through a food mill into a bowl or puree in a blender or food processor. Return to a clean pot and stir in the cream. Reheat, thinning as needed with equal parts broth and water. Taste and adjust the seasoning.
Divide among 4 warm bowls. Top each serving with a drizzle of crème fraîche and a sprinkling of chives, if desired.