MASHED SWEET POTATOES Servings Makes two to four cups Ingredients 2 large sweet potatoes peeled and cut into 1/2-inch pieces 1/2 teaspoon salt 3 tablespoons unsalted butter, softened Technique Cover sweet potatoes with water in a 2-quart heavy saucepan and add salt Cook, covered, over moderately high heat until tender, 15 to 20 minutes Drain sweet potatoes in a colander Transfer sweet potatoes to a bowl and mash with a potato masher. Mash together butter and salt and pepper to taste into sweet potatoes.