Creamy Gratin of Winter Vegetables

Preheat an oven to 350°F. Lightly butter a 12-inch flameproof gratin dish.

Peel the parsnips, rutabagas, turnip and potatoes and cut into 1-inch cubes. Put the vegetables in a stockpot, add water to cover by 4 to 5 inches and add the coarse sea salt. Bring to a boil over high heat, reduce the heat to medium and cook, uncovered, until the vegetables are easily pierced with a fork, about 25 minutes.

Drain the vegetables well and transfer to a large bowl. Sprinkle with the fine sea salt and pepper and stir several times.

In a saucepan over medium heat, combine the half-and-half, milk and the 2 Tbs. butter. Heat, stirring occasionally, just until tiny bubbles form along the edge of the pan.

Pour half of the milk mixture over the vegetables and mash coarsely with a potato masher. When the milk mixture has been absorbed, add the remaining milk mixture and 3 Tbs. of the parsley. Mash coarsely again until well blended. Spoon the mashed mixture into the prepared gratin dish, smoothing the surface. Sprinkle the cheeses on top. Cut the 1 tsp. butter into bits and dot the top.

Bake until bubbles begin to form along the edges and the top begins to turn golden, 15 to 20 minutes. Preheat the broiler and broil until the top is golden, 3 to 4 minutes. Remove from the broiler and sprinkle with the remaining 1 Tbs. parsley. Serve hot. Serves 8 to 10.

Adapted from Williams-Sonoma Entertaining with the Seasons (Free Press, 2010).