Sweet Potato Gratin

By Marge Perry & David Bonom
This incredibly rich, creamy, sweet dish will banish all thoughts of marshmallow-topped casseroles forever.
  • Cuisine: French
  • Course: Side Dish


  • chopped sage
  • chopped thyme
  • garlic cloves
  • ground black pepper
  • ground nutmeg
  • Gruyere cheese
  • heavy cream
  • onion
  • Sea salt
  • sharp cheddar cheese
  • Sweet potatoes
  • unsalted butter


  1. Combine the cream, butter, onion, garlic, nutmeg, salt and pepper in a small saucepan. Bring to a simmer over medium heat then immediately remove from the heat and let stand 15 minutes.
  2. Preheat the oven to 400°F. Lightly butter and 11x7-inch baking dish.
  3. Arrange 1/2 of the potatoes in the bottom of the prepared baking dish. Sprinkle with 1 1/2 of the sage and 1 teaspoon of the thyme then top with half of the cheeses. Repeat layering with remaining ingredients. Pour the cream mixture through a strainer over the baking dish. Cover with aluminum foil.
  4. Bake the sweet potatoes 40 minutes. Uncover, return to the oven and continue baking until the potatoes are tender, the liquid has thickened somewhat and the top is browned, about 30 minutes. Let stand at 15 minutes before serving.