Root Vegetable Gratin with Gruyère
- 1 Tbs. unsalted butter
- 3 garlic cloves, minced
- 3 cups heavy cream
- Salt and freshly ground pepper, to taste
- 1/4 tsp. freshly grated nutmeg
- 1 lb. parsnips, peeled and sliced 1/8 inch thick
- 1 lb. sweet potatoes, peeled and sliced 1/8 inch
- 1 lb. celery root, peeled and sliced 1/8 inch thick
- 8 oz. Gruyère cheese, shredded
- 1 Tbs. minced fresh thyme
- 3 Tbs. minced fresh flat-leaf parsley
In a large saucepan over medium heat, melt the butter. Add the garlic and cook for 1 minute. Add the cream, salt, pepper and nutmeg and heat just until bubbles form around the edges of the pan, about 5 minutes. Remove from the heat and let stand for 10 minutes.
Arrange a layer of parsnips, slightly overlapping, in the prepared dish. Arrange a layer of sweet potatoes on top, then a layer of celery root. Pour half of the cream mixture over the celery root, and sprinkle half of the cheese, thyme and parsley on top. Repeat with the remaining ingredients.
Cover the dish with aluminum foil, place on a baking sheet and bake for 1 hour. Remove the foil and lightly press the gratin down with a spatula. Continue baking until the vegetables are tender and the top is golden brown, 15 to 30 minutes more. Let the gratin stand for 15 minutes before serving. Serves 12 to 15.