Butternut Squash Gratin with tender slices of butternut squash layered with melted gruyere cheese in a creamy sage sauce and topped with a crispy Parmesan-walnut topping is an elegant side dish for Thanksgiving or dinner.
1. Preheat oven to 375°F. Heat olive oil in a skillet over medium heat. Sauté onion until tender, about 4 minutes. Add garlic, sage, brown sugar, salt, pepper, and nutmeg. Cook until fragrant, about 2 minutes. Remove from heat, stir in cream, and set aside.
2. Grease a 9"x13" baking dish and add water to the bottom. Layer ⅓ of the butternut squash, drizzle ⅓ of the cream mixture, and sprinkle ⅓ of the Gruyère. Repeat the layers of butternut, cream, cheese twice more.