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Spaghetti Squash Au Gratin Recipe

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★★★★★

4.7 from 680 reviews

This creamy and comforting Spaghetti Squash Au Gratin is a delicious low-carb alternative to traditional potato gratin. Roasted spaghetti squash is combined with a rich cheese sauce made from Gruyere, sharp cheddar, and Parmesan, then baked with a crunchy breadcrumb topping for a perfect golden crust. Ideal for a cozy weeknight dinner or a special holiday side dish, this recipe showcases the natural texture of spaghetti squash enhanced by a luscious, cheesy blend.

Ingredients

Scale

Squash

  • 1 large spaghetti squash (about 3–4 pounds)
  • 2 tablespoons unsalted butter, melted (for roasting)
  • Salt and black pepper, to taste

Cheese Sauce

  • 4 tablespoons unsalted butter
  • 1 medium yellow onion, finely chopped
  • 2 cloves garlic, minced
  • 4 tablespoons all-purpose flour
  • 3 cups whole milk
  • 1/2 teaspoon salt, plus more to taste
  • 1/4 teaspoon black pepper, plus more to taste
  • 1/4 teaspoon nutmeg
  • 3/4 cup grated Gruyere cheese
  • 3/4 cup grated sharp cheddar cheese
  • 1/4 cup grated Parmesan cheese

Topping

  • 1/4 cup grated Gruyere cheese
  • 1/4 cup grated sharp cheddar cheese
  • 1/4 cup grated Parmesan cheese
  • 1/4 cup panko breadcrumbs

Garnish

  • 2 tablespoons chopped fresh parsley (optional)

Instructions

  1. Preheat the Oven: Set your oven to 400°F (200°C) to prepare for roasting the spaghetti squash.
  2. Prepare the Squash: Carefully cut the spaghetti squash in half lengthwise and scoop out the seeds and stringy bits from the center.
  3. Season the Squash: Drizzle the cut sides of the squash halves with 2 tablespoons of melted butter, then generously sprinkle with salt and black pepper for flavor.
  4. Roast the Squash: Place the squash halves cut-side down on a parchment-lined baking sheet. Roast in the oven for 45 to 60 minutes, or until the flesh is tender and easily pierced with a fork.
  5. Shred the Squash: Let the roasted squash cool enough to handle, then use a fork to shred the flesh into spaghetti-like strands. Set aside.
  6. Melt Butter in Saucepan: In a large saucepan over medium heat, melt the remaining 2 tablespoons of butter to start the sauce.
  7. Sauté Onion and Garlic: Add the finely chopped onion to the melted butter and cook for 5-7 minutes until softened and translucent. Stir in minced garlic and cook for an additional minute until fragrant.
  8. Make Roux: Sprinkle the flour over the cooked onion and garlic, stirring constantly for 1-2 minutes to form a roux, which will thicken the sauce.
  9. Add Milk: Gradually whisk in the milk a little at a time to avoid lumps, continuing until the sauce becomes smooth.
  10. Simmer the Sauce: Bring the mixture to a simmer over medium heat, stir constantly, then reduce the heat to low and let it simmer 5-7 minutes until slightly thickened.
  11. Season the Sauce: Add salt, black pepper, and nutmeg. Taste and adjust seasonings as needed for a balanced flavor.
  12. Add Cheese: Remove the pan from heat and stir in 3/4 cup Gruyere, 3/4 cup cheddar, and 1/4 cup Parmesan until the cheese melts completely and the sauce is creamy.
  13. Combine Squash and Sauce: Gently fold the shredded spaghetti squash into the cheese sauce, ensuring an even coating.
  14. Transfer to Baking Dish: Pour the cheesy squash mixture into a greased 9×13 inch baking dish, spreading it out evenly.
  15. Prepare the Topping: In a small bowl, mix the remaining 1/4 cup Gruyere, 1/4 cup cheddar, 1/4 cup Parmesan, and the panko breadcrumbs.
  16. Sprinkle the Topping: Evenly distribute the cheese and breadcrumb mixture over the top of the squash in the baking dish.
  17. Bake Au Gratin: Return the dish to the oven and bake for 20-25 minutes until the topping is golden brown and bubbly.
  18. Let it Rest: Remove from the oven and allow the dish to rest for 5-10 minutes to set.
  19. Garnish and Serve: Garnish with chopped fresh parsley if desired. Serve hot and enjoy this creamy, cheesy spaghetti squash au gratin.

Notes

  • Use a fork to test the tenderness of the roasted spaghetti squash to ensure it’s fully cooked before shredding.
  • You can substitute whole milk with 2% milk, but avoid skim for best sauce creaminess.
  • For a crispier topping, broil the au gratin for 1-2 minutes at the end of baking, watching closely to prevent burning.
  • Gruyere cheese is preferred for its melting quality and flavor, but Swiss cheese can be a substitute if unavailable.
  • Leftovers can be refrigerated in an airtight container for up to 3 days and reheated in the oven for best texture.

Keywords: spaghetti squash, au gratin, cheesy, roasted squash, low carb side, vegetable gratin, comfort food

Find it online: https://thehungrymason.com/spaghetti-squash-au-gratin-recipe/