2 lb parsnips, peeled and cut into 1-inch pieces 2 lb russet (baking) potatoes, peeled and cut into 2-inch pieces 1 tablespoon plus 1/2 teaspoon salt 1 cup heavy cream 1/2 stick ( cup) unsalted butter teaspoon black pepper Special equipment: a potato ricer or a food mill fitted with medium disk (If you don't have a ricer or food mill, you can also use a hand mixer.)
Cover parsnips and potatoes with cold water by 1 inch in a 6- to 8-quart pot, then add 1tablespoon salt and bring to a boil, partially covered. Reduce heat and simmer vegetables, partially covered, until very tender but not falling apart, 30 to 40 minutes. Meanwhile, bring cream, butter, pepper, and remaining 1/2 teaspoon salt to a simmer in 4-quart heavy pot over moderate heat. Drain vegetables in a colander. Force warm vegetables through ricer into cream mixture, then stir to combine well. Cooks' note: Potato parsnip purée can be made 1 day ahead and chilled in a baking dish, covered. Bring to room temperature and reheat, covered, in a preheated 450°F oven until hot, about 20 minutes, or in a microwave. - Updated: March 14, 2005
