Method
- Preheat the oven to 375°F.
- Prepare the squash: Cut the butternut squash in half, scoop out the seeds, peel, and slice thinly into half-moons using a mandolin or sharp knife.20 ounces butternut squash
- Mix the cream: In a bowl, whisk together the heavy cream, salt, black pepper, nutmeg, and garlic powder.1 cup heavy cream, ½ teaspoon salt, ¼ teaspoon nutmeg, ¼ teaspoon black pepper, ½ teaspoon garlic powder
- Grease the pan: Lightly grease a 2-quart baking dish with butter or olive oil.1 tablespoon olive oil
- Layer the squash: Arrange half of the squash slices in the bottom of the dish. I like to use irregular pieces on the bottom and save the more uniform slices for the top.
- Add the cream and cheese: Pour ⅓ of the cream mixture over the squash and sprinkle with grated cheese.1 ¼ cup Gruyère cheese
- Repeat the layers: Add the remaining squash slices, tucking sage leaves between some of the layers. Pour over the rest of the cream mixture and top with the remaining grated cheese.5 sage leaves or thyme sprigs
- Bake covered: Cover the dish with foil and bake for 45 minutes.
- Bake uncovered: Remove the foil and bake for another 15 minutes, or until the top is golden brown and bubbly.
For a crispy sage topping (optional):
- Melt butter: In a skillet over medium heat, melt 1 tablespoon of butter.
- Crisp the sage: Add 4-5 sage leaves and cook for about 30 seconds per side until crisp.
- Drain: Transfer to a paper towel to absorb excess oil, then sprinkle over the casserole before serving.