Print

Spaghetti Squash Recipe

Print Recipe

★★★★★

4.6 from 125 reviews

This rich and comforting Spaghetti Squash Au Gratin recipe transforms tender roasted spaghetti squash into a creamy, cheesy casserole loaded with Gruyere, sharp cheddar, and Parmesan cheeses. The squash is roasted to perfection, mixed with a smooth béchamel sauce infused with sautéed onions, garlic, nutmeg, and finished with a golden breadcrumb topping. Perfect as a hearty side dish or a satisfying vegetarian main.

Ingredients

Scale

Squash

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

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 (optional)

  • 2 tablespoons chopped fresh parsley

Instructions

  1. Preheat the oven: Set your oven to 400°F (200°C) to prepare for roasting the squash and baking the casserole.
  2. Prepare the spaghetti squash: Carefully cut the squash in half lengthwise and scoop out the seeds and any stringy fibers from the center.
  3. Season the squash: Drizzle the cut sides with 2 tablespoons of melted butter and generously sprinkle with salt and black pepper.
  4. Roast the squash: Place the squash halves cut-side down on a parchment-lined baking sheet and roast in the oven for 45-60 minutes until the squash flesh is tender and easily pierced with a fork.
  5. Shred the squash: When cool enough to handle, use a fork to scrape the flesh into spaghetti-like strands and set aside.
  6. Melt the butter: In a large saucepan over medium heat, melt the remaining 2 tablespoons of butter to begin your sauce base.
  7. Sauté onions and garlic: Add the finely chopped onion to the melted butter and cook until softened and translucent, about 5-7 minutes. Stir in the minced garlic and cook for another minute until fragrant.
  8. Make the roux: Sprinkle the all-purpose flour over the onion and garlic mixture and cook, stirring constantly, for 1-2 minutes to form a roux, which will thicken the sauce.
  9. Whisk in the milk: Gradually add the whole milk, whisking constantly to prevent lumps. Continue whisking until the mixture is smooth.
  10. Simmer the sauce: Bring the sauce to a gentle simmer over medium heat, stirring continuously. Reduce heat to low and simmer for 5-7 minutes until the sauce slightly thickens.
  11. Season the sauce: Stir in salt, black pepper, and nutmeg. Taste and adjust seasoning as needed for balanced flavor.
  12. Add the cheese: Remove the saucepan from heat and stir in 3/4 cup Gruyere, 3/4 cup sharp cheddar, and 1/4 cup Parmesan cheese until melted and the sauce is creamy.
  13. Combine squash and sauce: Gently fold the shredded spaghetti squash into the cheese sauce ensuring even coating.
  14. Transfer to baking dish: Pour the mozzarella-coated squash mixture into a greased 9×13 inch baking dish, spreading evenly.
  15. Prepare the topping: In a small bowl, combine the remaining 1/4 cup Gruyere, 1/4 cup cheddar, 1/4 cup Parmesan, and panko breadcrumbs.
  16. Sprinkle the topping: Evenly distribute the cheese and breadcrumb mixture over the top of the casserole.
  17. Bake the au gratin: Bake in the preheated oven for 20-25 minutes or until the topping is golden brown and bubbling beautifully.
  18. Let it rest: Remove from oven and allow the casserole to rest for 5-10 minutes to set and cool slightly.
  19. Garnish and serve: Sprinkle chopped fresh parsley over the casserole if desired. Serve warm and enjoy the creamy, cheesy delight.

Notes

  • For a nuttier flavor, try substituting the Gruyere with Fontina or Swiss cheese.
  • Leftover casserole can be refrigerated for up to 3 days and reheated in the oven to retain crisp topping.
  • To make this dish gluten-free, substitute all-purpose flour with a gluten-free flour blend and use gluten-free panko breadcrumbs.
  • Roasting time may vary depending on the size of the squash; check for tenderness periodically after 45 minutes.
  • For extra flavor, consider adding a pinch of smoked paprika or cayenne pepper to the cheese sauce.

Keywords: Spaghetti squash, spaghetti squash au gratin, cheesy squash casserole, vegetarian squash recipe, comfort food, roasted squash, autumn side dish

Find it online: https://cheframi.com/spaghetti-squash-recipe/