Truffled Potato and Celery Root Gratin

Serves 12

2 cups heavy cream
1 cup chicken stock
2 tablespoons black truffle paste
1-1/2 teaspoons kosher salt
1/2 teaspoon freshly ground black pepper
4 large shallots, peeled and thinly sliced (about 3/4 cup)
2 pounds celery root, peeled, halved, and thinly sliced
2 pounds russet potatoes, peeled and thinly sliced
8 ounces Fontina Val d'Aosta cheese, shredded

Heat the oven to 400 F.

In a saucepan, combine the cream and chicken stock and bring to a simmer over medium heat. Stir in the truffle paste, salt, and pepper and remove from the heat.

In a 15-by-10-by-2-inch baking dish, layer half the shallots with half the celery root, half the potatoes, and half the cream mixture. Repeat with the remaining shallots, celery root, potatoes, and cream mixture. Push down on the ingredients with a spatula, cover tightly with foil, and bake until the vegetables can be easily pierced with the tip of a knife, about 1 hour. Increase the oven temperature to 450 F, remove the foil, and bake until the liquid begins to thicken, 10 to 15 minutes. Sprinkle the cheese evenly over the surface, and continue baking until the cheese has melted and begins to brown, about 15 minutes. Remove from the oven and let cool for 15 minutes before serving.