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Spaghetti Squash Au Gratin Recipe

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★★★★★

4.7 from 59 reviews

Spaghetti Squash Au Gratin is a comforting and creamy baked casserole that replaces traditional potatoes with nutritious spaghetti squash. Roasted until tender, the squash is combined with a rich cheese sauce made from Gruyere, sharp cheddar, and Parmesan, then topped with a golden, crispy breadcrumb and cheese crust. This dish offers a delicious, lower-carb alternative to classic gratins, perfect for a cozy family dinner or special occasion.

Ingredients

Scale

Spaghetti Squash

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

Cheese Sauce

  • 2 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 Oven: Set your oven to 400°F (200°C) to prepare for roasting the spaghetti squash.
  2. Prepare the Squash: Cut the spaghetti squash in half lengthwise and scoop out the seeds and stringy bits carefully.
  3. Season the Squash: Drizzle 2 tablespoons of melted butter over the cut sides of the squash and season generously with salt and black pepper.
  4. Roast the Squash: Place the squash halves cut-side down on a baking sheet lined with parchment paper. Roast for 45-60 minutes until the flesh is tender and easily pierced with a fork.
  5. Shred the Squash: After the squash cools enough to handle, use a fork to scrape the flesh into spaghetti-like strands. Set aside.
  6. Melt Butter: In a large saucepan over medium heat, melt the remaining 2 tablespoons of butter.
  7. Sauté Onion and Garlic: Add the finely chopped onion and cook for 5-7 minutes until softened and translucent. Add minced garlic and cook another minute until fragrant.
  8. Make Roux: Sprinkle the flour over the onion and garlic mixture, stirring constantly for 1-2 minutes to cook the flour.
  9. Whisk in Milk: Gradually add the milk, whisking continuously to prevent lumps and create a smooth sauce.
  10. Simmer Sauce: Bring the sauce to a simmer over medium heat, then reduce heat to low and simmer for 5-7 minutes until thickened slightly.
  11. Season Sauce: Stir in salt, pepper, and nutmeg. Adjust seasoning to taste.
  12. Add Cheese to Sauce: Remove saucepan from heat and stir in 3/4 cup Gruyere, 3/4 cup cheddar, and 1/4 cup Parmesan until melted and creamy.
  13. Combine Squash and Sauce: Gently stir the shredded spaghetti squash into the cheese sauce until well combined.
  14. Transfer to Baking Dish: Pour the mixture into a greased 9×13 inch baking dish, spreading evenly.
  15. Prepare Topping: In a small bowl, mix remaining 1/4 cup Gruyere, 1/4 cup cheddar, 1/4 cup Parmesan, and panko breadcrumbs.
  16. Sprinkle Topping: Evenly distribute the cheese and breadcrumb mixture over the top of the casserole.
  17. Bake Au Gratin: Bake in the preheated oven for 20-25 minutes until the topping is golden brown and bubbly.
  18. Rest the Dish: Remove from oven and let rest for 5-10 minutes before serving to set.
  19. Garnish and Serve: Sprinkle chopped fresh parsley on top if desired, and serve hot for best flavor.

Notes

  • Do not overcook the spaghetti squash to avoid mushy texture.
  • Use high-quality cheeses for richest flavor.
  • Adjust seasoning like salt and pepper to suit your taste preferences.
  • This gratin can be assembled a day ahead and refrigerated; increase baking time by a few minutes if baking from cold.
  • Add a pinch of red pepper flakes in the cheese sauce for a subtle kick.
  • Experiment with different cheese varieties for unique flavor profiles.
  • For a more filling meal, consider adding cooked bacon, ham, or sausage to the squash mixture.
  • Ensure Parmesan is vegetarian-friendly, as some contain animal rennet.

Keywords: Spaghetti Squash, Au Gratin, Cheese Casserole, Vegetarian, Low Carb, Comfort Food, Gruyere, Cheddar, Parmesan, Roasted Squash

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