Ingredients
3
lb celery root (sometimes called celeriac; 2 large), peeled with a knife and cut into 1/2-inch pieces (8 cups)
1
3/4 lb boiling potatoes (3 large), peeled and cut into 1/2-inch pieces
4
oz black truffle butter* or 1 stick (1/2 cup) unsalted butter
Directions
1.
Cover celery root and potatoes with cold salted water by 2 inches in a 4- to 6-quart heavy pot, then simmer, covered, until celery root is very tender, about 15 minutes.
2.
While vegetables are simmering, bring cream, truffle butter, salt, and pepper just to a simmer, stirring until butter is melted.
3.
Drain vegetables in a colander and transfer to a food processor. Add hot cream mixture in a steady stream, pulsing until smooth. (Alternatively, mash vegetables with hot cream mixture using a potato masher.)
5.
Purée can be made 1 day ahead and cooled, uncovered, then chilled, covered. Reheat in an ovenproof dish, covered, in the oven or microwave until hot.
6.
*Available at specialty foods shops and D\'Artagnan (800-327-8246).
New-York Restaurants
