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Pour the spaghetti squash mixture into a greased 9×13 inch baking dish Recipe

Pour the spaghetti squash mixture into a greased 9x13 inch baking dish Recipe
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Spaghetti Squash Au Gratin is a comforting, cheesy casserole that transforms healthy spaghetti squash into a rich, creamy dish. Roasted spaghetti squash strands are mixed with a luscious cheese sauce made from Gruyere, sharp cheddar, and Parmesan, then baked with a crunchy panko topping. This recipe is a delicious low-carb alternative to traditional potato au gratin and perfect for a nutritious family meal.

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: Preheat your oven to 400°F (200°C) to ensure it is ready for roasting the squash and baking the casserole.
  2. Prepare the Squash: Cut the spaghetti squash lengthwise in half and scoop out the seeds and stringy bits to clean the inside cavities.
  3. Season the Squash: Drizzle the cut sides with 2 tablespoons of melted butter and season generously with salt and pepper to enhance flavor.
  4. Roast the Squash: Place the squash halves cut-side down on a baking sheet lined with parchment paper. Roast in the preheated oven for 45-60 minutes, until the flesh is tender and can be easily pierced with a fork.
  5. Shred the Squash: Allow the roasted squash to cool enough to handle, then use a fork to scrape out 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 to start the cheese sauce base.
  7. Sauté Onion and Garlic: Add the finely chopped onion and cook until softened and translucent, about 5-7 minutes. Add minced garlic and cook for an additional minute until fragrant.
  8. Make Roux: Sprinkle the flour over the cooked onion and garlic mixture. Stir constantly and cook for 1-2 minutes to form a roux, which will thicken the sauce.
  9. Whisk in Milk: Gradually add the milk a little at a time while whisking continuously to prevent lumps, creating a smooth base sauce.
  10. Simmer Sauce: Bring the mixture to a gentle simmer over medium heat, stirring constantly. Reduce the heat to low and allow the sauce to thicken for 5-7 minutes.
  11. Season Sauce: Stir in salt, black pepper, and nutmeg. Taste and adjust seasoning as needed to your preference.
  12. Add Cheese: Remove the saucepan from heat. Stir in 3/4 cup Gruyere, 3/4 cup cheddar, and 1/4 cup Parmesan until melted and the sauce is creamy and smooth.
  13. Combine Squash and Sauce: Gently fold the shredded spaghetti squash into the cheese sauce to evenly coat all the strands.
  14. Transfer to Dish: Pour the mixture into a greased 9×13-inch baking dish, spreading it out evenly.
  15. Prepare Topping: In a small bowl, mix together the remaining 1/4 cup Gruyere, 1/4 cup cheddar, 1/4 cup Parmesan, and panko breadcrumbs.
  16. Sprinkle Topping: Evenly scatter the cheese and breadcrumb topping over the surface of the casserole.
  17. Bake au Gratin: Place the baking dish in the oven and bake for 20-25 minutes or until the topping is golden brown and bubbling.
  18. Rest: Remove from the oven and let the casserole rest for 5-10 minutes to set before serving.
  19. Garnish and Serve: Optionally garnish with freshly chopped parsley. Serve hot and enjoy your creamy, cheesy spaghetti squash au gratin!

Notes

  • Roast the squash ahead of time to save prep time when ready to assemble the gratin.
  • For a lower fat version, substitute milk with 2% or use half-and-half for extra richness.
  • Panko breadcrumbs add crunch but can be omitted or replaced with crushed nuts for gluten-free option.
  • Freshly grate cheeses for best melting and flavor; pre-shredded cheeses often contain anti-caking agents that affect texture.
  • Leftovers can be stored covered in the fridge for up to 3 days and reheated in the oven.
  • This dish pairs wonderfully with a crisp green salad and roasted vegetables.

Nutrition

Keywords: spaghetti squash au gratin, cheesy spaghetti squash casserole, healthy au gratin recipe, low-carb side dish, vegetable casserole, vegetarian casserole

Find it online: https://cookwithlea.com/pour-the-spaghetti-squash-mixture-into-a-greased-9x13-inch-baking-dish-recipe/