Ingredients

Serves 6

　　5 pounds sweet potatoes (about 6 large)

　　3 or 4 dried ancho chiles (about 1 1/2 ounces)

　　3/4 cup heavy cream

　　2 teaspoons salt

　　2 tablespoons unsalted butter, or to taste

　　

Step 1

Preheat oven to 450°F. and line a baking sheet with foil.

　　

Step 2

Prick sweet potatoes in several places with a fork and bake on baking sheet in middle of oven until tender, about 1 hour. Cool potatoes until they can be handled.

　　

Step 3

Wearing rubber gloves, stem and seed chiles and tear into 1-inch pieces. In a small saucepan bring chiles and cream to a boil. In a blender purée mixture until smooth (use caution when blending hot liquids).

　　

Step 4

Scoop flesh from potatoes into a food processor, discarding skins, and purée with cream mixture, salt, and 2 tablespoons butter. Purée may be made up to this point 1 day ahead and cooled before being chilled, covered.

　　

Step 5

Transfer purée to a large saucepan and heat over moderate heat, stirring, until hot, stirring in more salt and butter if desired.