Creamy Butternut Squash Gratin
This scalloped butternut squash gratin is made with caramelized onions, sage, garlic, and thyme in a creamy sauce, layered and topped with Parmesan cheese and breadcrumbs then baked until golden and bubbling.
Servings 8 servings
Ingredients
- 1 butternut squash about 2 pounds
- 4 tablespoons butter
- 1 large onion sliced
- 4 garlic cloves
- 12 sage leaves cut into thin strips
- 1 tablespoon fresh thyme leaves
- 1 teaspoon sea salt
- ½ teaspoon black pepper
- ⅛ teaspoon nutmeg
- 1 cup heavy cream
- ½ cup grated Parmesan cheese
- ¼ cup breadcrumbs
Instructions
- Preheat oven to 375°F. Peel 1 butternut squash and cut lengthwise. Remove seeds and pith. Thinly slice crosswise into ⅛-inch thick circles. You can also cut into half-moons.
- Melt 4 tablespoons butter in a large skillet over medium heat. Add sliced 1 large onion sliced and season with salt to release juices. Cook until onions are caramelized (approximately 25 minutes), stirring occasionally.
- Add 4 garlic cloves, 12 sage leaves, 1 tablespoon fresh thyme leaves, and season with 1 teaspoon sea salt, ½ teaspoon black pepper, and ⅛ teaspoon nutmeg and cook just until fragrant.
- Reduce heat to medium-low and add 1 cup heavy cream. Whisk to combine everything and cook until cream sauce has thickened.
- Spoon ¼ of the onion cream mixture to the bottom of the casserole dish. Arrange odds and ends of butternut squash slices across the dish, overlapping slightly. Spoon another ¼ of the cream onion mixture. Add a second layer of the butternut squash, followed by the 3rd ¼ of the onion cream mixture. Add the final layer of butternut squash, overlapping and pressing down so the top is flat all across the baking dish. Drizzle the remaining onion mixture.
- Spread the cream onion sauce evenly to cover the squash. Sprinkle with ½ cup grated Parmesan cheese and ¼ cup breadcrumbs. Add extra sage leaves on top.
- Cover with a piece of parchment paper then aluminum foil. Bake covered for 40 minutes on the middle rack. Remove the cover and bake for 10 more minutes to brown the tops. Remove from oven and allow to rest for 5 minutes for sauce to settle before serving.
Video
Notes
Note: Recipe was originally published in 2016 but has since been modified to omit arrowroot starch as video shows.
Storage: Gratin can be stored in an airtight container in the fridge for up to 4 days. Reheat in a 350°F (175°C) oven for 15-20 minutes until warmed through. You can also freeze it for up to 2 months; wrap tightly with plastic wrap and foil. Thaw in the refrigerator overnight and reheat in the oven, adding 5-10 extra minutes to ensure it is heated evenly.
Helpful Tips:
- Caramelize onions - stir onions occasionally but don't rush them; slow cooking develops deel flavor.
- Slice thin and uniform - cut the butternut squash very thinly (⅛th of an inch) and as evenly as possible so it cooks consistently and layers neatly.
- Use odds and ends first - place the irregular or smaller pieces on the bottom layer and reserve the most perfect half-moons for the top layer to make the gratin look appealing.
- Brown the top - broil the last few minutes of cook time to brown and crisp the tops
Nutrition
Calories: 242kcal | Carbohydrates: 17g | Protein: 4g | Fat: 18g | Saturated Fat: 11g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 5g | Trans Fat: 0.2g | Cholesterol: 54mg | Sodium: 482mg | Potassium: 412mg | Fiber: 2g | Sugar: 4g | Vitamin A: 10675IU | Vitamin C: 23mg | Calcium: 138mg | Iron: 1mg