Spaghetti Squash Au Gratin Recipe – Easy Yummy Healthy Dinner (Gluten-Free!)

Golden, cheesy, and irresistibly comforting—this Spaghetti Squash Au Gratin Recipe proves that healthy dinners can still feel indulgent. Fresh from the oven with a bubbling cheese topping and creamy sauce, this dish delivers all the cozy satisfaction of a classic casserole while staying lighter and naturally gluten-friendly.

Spaghetti squash is perfect for creating Easy Yummy Healthy Dinners because it transforms into tender pasta-like strands once roasted. That makes it a wonderful option for Gluten Free Meals Dinners Main Dishes that still feel hearty and satisfying.

This dish can easily serve as a main meal or one of those comforting Easy Veggie Sides Healthy enough to pair with roasted chicken, grilled steak, or fish.

Many home cooks search for ideas about What To Make With Spaghetti Squash, and this cheesy gratin is one of the best answers. The roasted squash blends beautifully with creamy cheese sauce and a crispy golden topping.

Even fans of Sweet Spaghetti Squash Recipes will enjoy how the natural sweetness of the squash balances the rich savory cheese sauce. Among popular Spaghetti Squash Recipes Sweet and savory options, this one stands out for its comforting flavor and satisfying texture.

Still deciding What To Serve With Spaghetti Squash? This creamy casserole pairs beautifully with salads, roasted meats, or grilled vegetables for a complete meal.

Spaghetti Squash Au Gratin

Ingredients

• 1 large spaghetti squash (3–4 pounds)
• 4 tablespoons unsalted butter, divided
• 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
• 1/4 teaspoon nutmeg
• 1 cup grated Gruyere cheese, divided
• 1 cup grated sharp cheddar cheese, divided
• 1/2 cup grated Parmesan cheese, divided
• 1/4 cup panko breadcrumbs
• 2 tablespoons chopped fresh parsley (optional)

Instructions

1. Preheat oven to 400°F (200°C).
2. Cut the spaghetti squash in half lengthwise and remove the seeds and fibrous center.
3. Brush the cut sides with 2 tablespoons melted butter and season generously with salt and pepper.
4. Place the squash halves cut-side down on a parchment-lined baking sheet and roast for 45–60 minutes until tender.
5. Allow the squash to cool slightly, then scrape the flesh with a fork to create spaghetti-like strands. Set aside.
6. In a large saucepan, melt the remaining 2 tablespoons butter over medium heat.
7. Add the chopped onion and cook for 5–7 minutes until soft and translucent. Stir in the garlic and cook for another minute.
8. Sprinkle the flour over the mixture and cook while stirring for 1–2 minutes to form a roux.
9. Slowly whisk in the milk, stirring constantly until the sauce becomes smooth.
10. Bring the mixture to a gentle simmer and cook for 5–7 minutes until slightly thickened.
11. Season the sauce with salt, pepper, and nutmeg.
12. Remove from heat and stir in 3/4 cup Gruyere, 3/4 cup cheddar, and 1/4 cup Parmesan until melted and creamy.
13. Add the spaghetti squash strands to the cheese sauce and gently mix.
14. Transfer the mixture to a greased 9×13-inch baking dish.
15. Combine the remaining cheeses with the panko breadcrumbs and sprinkle over the top.
16. Bake for 20–25 minutes until the topping is golden and bubbling.
17. Allow the dish to rest for 5–10 minutes before serving.
18. Garnish with chopped parsley if desired and serve hot.

Notes

• Avoid overcooking the squash so the strands stay firm.
• High-quality cheese improves the flavor of the sauce.
• Season to taste before baking.
• This dish can be assembled ahead and refrigerated for up to 24 hours.
• Add red pepper flakes for a little heat.
• Cooked bacon, ham, or sausage can be added for a heartier meal.