Spaghetti Squash Au Gratin Delight

This creamy Spaghetti Squash Au Gratin takes tender strands of roasted squash and bakes them in a rich cheese sauce topped with a golden, bubbly crust. It’s a satisfying and healthier alternative to traditional macaroni and cheese, perfect for cooler evenings or when you want comfort food without the heaviness.

I first made this when looking for a gluten-free alternative to mac and cheese, and it quickly became a family favorite. Now it’s one of the go-to dishes for cozy dinners.

Gather Your Ingredients

• One large spaghetti squash: about 3 to 4 pounds which when roasted creates tender strands resembling noodles
• Unsalted butter: to build a flavorful base and add richness
• Medium yellow onion: finely chopped to bring sweetness and depth
• Fresh garlic: minced to add aromatic sharpness
• All-purpose flour: helps thicken the cheese sauce into a smooth consistency
• Whole milk: lends creaminess and balances cheese flavors better than cream alone
• Salt and black pepper: for essential seasoning adjustments
• Nutmeg: adds subtle warmth complementing the richness without overpowering
• Gruyere cheese: known for its nutty and slightly sweet flavor melts beautifully
• Sharp cheddar cheese: provides a tangy bite that balances the milder Gruyere
• Parmesan cheese: gives salty umami and enhances the crust’s flavor
• Panko breadcrumbs: for a crunchy topping that stays crisp even after baking
• Fresh chopped parsley: for a fresh garnish and visual appeal

How to Make It

Slicing and Preparing the Squash:

Cut the squash in half lengthwise using a sharp knife. Scoop out the seeds and stringy bits carefully so you have a clean cavity to roast.

Seasoning and Roasting:

Brush the cut sides generously with half of the melted butter and season with salt and pepper. Place the halves cut-side down on a lined baking sheet and roast in a preheated 400 degree Fahrenheit oven for 45 to 60 minutes until a fork easily pierces the flesh.

Shredding the Squash:

Once cool enough to handle, use a fork to scrape out the strands, which will look like tiny noodles. Set these aside while you prepare the cheese sauce.

Making the Cheese Sauce Base:

Melt the remaining butter in a large saucepan over medium heat. Add the chopped onion and cook gently until translucent and soft, about 5 to 7 minutes. Stir in minced garlic and cook for another minute to bring out its fragrance without burning.

Creating the Roux and Adding Milk:

Sprinkle flour over the onion and garlic mixture and stir constantly for a minute or two to form a roux that will thicken the sauce. Gradually whisk in the milk slowly to avoid lumps, continuing until the sauce is smooth.

Simmering and Seasoning:

Bring the sauce to a gentle simmer, reducing heat to low, and let it thicken for 5 to 7 minutes while stirring often. Add salt, pepper, and nutmeg adjusting to taste for a balanced flavor.

Adding the Cheese:

Remove the pan from heat and stir in the majority of the Gruyere, cheddar, and Parmesan until melted and the sauce is creamy and smooth, reserving some cheese for the topping.

Combining Squash and Sauce:

Gently fold the shredded spaghetti squash into the cheese sauce making sure the strands are evenly coated without breaking them up too much.

Transferring to Baking Dish:

Pour the cheesy squash mixture into a large greased baking dish about 9 by 13 inches, spreading evenly.

Preparing the Topping:

Mix together the reserved cheeses and panko breadcrumbs in a small bowl to create a crunchy, cheesy topping.

Baking the Au Gratin:

Sprinkle the topping evenly over the casserole and bake at 400 degrees Fahrenheit for 20 to 25 minutes until the surface is golden and bubbling.

Resting Before Serving:

Remove from the oven and allow it to sit for 5 to 10 minutes to let everything set, making it easier to serve without falling apart.

Garnishing and Serving:

Sprinkle with fresh parsley if desired and serve hot for the best creamy and crunchy combination.

This recipe shines because of the balance between the creamy sauce and the crunchy topping, and my favorite part is the Gruyere cheese which adds a subtle, nutty sweetness that the whole family loves. I remember serving this at a holiday dinner, and even my cheese-averse guests asked for seconds.

Flavor Boosters

Pair this au gratin with a simple green salad tossed in a light vinaigrette to balance the richness. Serve alongside roasted vegetables or a protein like grilled chicken or pork chops. A crisp white wine such as Sauvignon Blanc complements the cheesy flavors wonderfully.

Serving Suggestions

Store leftovers covered tightly in the refrigerator and consume within 3 to 4 days for best freshness. Reheat in the oven at moderate temperature to restore crispiness to the top instead of microwave which can make it soggy. This dish can be assembled ahead of time and refrigerated for up to 24 hours; just add extra baking time if baking from cold.

Creative Twists

Use the squash when in peak season during fall and early winter for best flavor and texture. For a spring variation, add steamed asparagus or peas into the cheese sauce before baking. Try mixing in fresh herbs like thyme or rosemary in colder months for added warmth and fragrance.

This recipe delivers comfort and flavor with a wholesome twist perfect for any occasion.

Common Questions About the Recipe

→ How do you prepare the spaghetti squash for this dish?

Slice the squash in half lengthwise, scoop out seeds, roast cut-side down until tender, then shred the flesh with a fork into noodle-like strands.

→ What cheeses are best for the creamy sauce?

Gruyere, sharp cheddar, and Parmesan provide a rich, layered flavor and creamy texture when melted into the sauce.

→ How is the creamy cheese sauce made?

A roux is made with butter and flour, then milk is whisked in and simmered until thickened. Cheese is added off the heat to melt smoothly.

→ What ensures the topping becomes golden and crispy?

A blend of grated cheeses combined with panko breadcrumbs is sprinkled on top, then baked until bubbly and golden brown.

→ Can this dish be made ahead of time?

Yes, it can be assembled in advance and refrigerated for up to 24 hours. Add a few extra minutes to baking if starting cold.

→ How can I add more flavor or texture variations?

Try adding cooked bacon, ham, or sausage to the squash mix, or a pinch of red pepper flakes to the cheese sauce for a spicy kick.