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

If you’re ready to dive into a dish that’s both comforting and fresh, this Spaghetti Squash Au Gratin will be your new favorite weeknight champion. Imagine tender strands of roasted spaghetti squash enrobed in a luscious, creamy cheese sauce, all topped with a perfectly golden, crunchy crust — now, to bring it all together, you’ll pour the spaghetti squash mixture into a greased 9×13 inch baking dish, making sure every bit gets baked to cheesy perfection. This recipe balances healthiness and indulgence with beautiful layers of flavor and texture, proving that wholesome can absolutely mean delicious.

Ingredients You’ll Need

This recipe is wonderfully straightforward, relying on simple ingredients that each play a key role in creating the perfect au gratin texture and flavor. From the natural sweetness of the roasted squash to the rich blend of cheeses, every element brings something special to the table.

• 1 large spaghetti squash (about 3-4 pounds): The star of the dish, providing a light, spaghetti-like base that’s low in carbs but full of texture.
• 4 tablespoons unsalted butter, divided: Adds a velvety depth in the sauce and helps soften the aromatics.
• 1 medium yellow onion, finely chopped: Offers a sweet, savory backbone to the creamy mixture.
• 2 cloves garlic, minced: Brings a subtle pungency that lifts the flavor profile.
• 4 tablespoons all-purpose flour: Essential for thickening the sauce into a smooth, luscious consistency.
• 3 cups whole milk: Creates a creamy base that’s just rich enough with a silky mouthfeel.
• 1/2 teaspoon salt, plus more to taste: Enhances every flavor without overpowering.
• 1/4 teaspoon black pepper, plus more to taste: Adds a gentle heat that balances the richness.
• 1/4 teaspoon nutmeg: A classic touch in creamy cheese sauces that adds warmth and sophistication.
• 1 cup grated Gruyere cheese, divided: Melts beautifully to give a slightly nutty, creamy texture.
• 1 cup grated sharp cheddar cheese, divided: Introduces a tangy bite that complements the milder Gruyere.
• 1/2 cup grated Parmesan cheese, divided: Adds a salty, umami hit and helps with a golden crust.
• 1/4 cup panko breadcrumbs: For a crisp, airy topping that contrasts the creamy squash.
• 2 tablespoons chopped fresh parsley, for garnish (optional): Adds a fresh, herby brightness to finish.

How to Make Pour the spaghetti squash mixture into a greased 9×13 inch baking dish

Step 1: Roast the Spaghetti Squash

Begin by preheating your oven to 400°F (200°C). Cut the spaghetti squash in half lengthwise, then scoop out the seeds and stringy bits to reveal that golden flesh. Drizzle each half with 2 tablespoons of melted butter, sprinkle generously with salt and pepper, and place them cut-side down on a parchment-lined baking sheet. Roast for 45-60 minutes until the squash is tender enough to be shredded easily with a fork. This step unlocks the squash’s natural sweetness and gives you that wonderful “spaghetti” texture.

Step 2: Prepare the Cheese Sauce

While your squash cools, melt the remaining 2 tablespoons of butter in a large saucepan over medium heat. Add the finely chopped onion and cook it slowly until it’s soft and translucent, about 5-7 minutes. Toss in the minced garlic and cook for an additional minute until fragrant — don’t rush here, this is where depth builds. Sprinkle the flour over the butter, onion, and garlic, stirring constantly to form a roux. This acts as the magic thickener for your sauce.

Step 3: Whisk in Milk and Season

Gradually add the whole milk to the roux, whisking all the while to avoid lumps and create a silky smooth sauce. Bring it up to a gentle simmer, stirring often until the sauce thickens just slightly, about 5-7 minutes. Next, season with salt, pepper, and a pinch of nutmeg to taste. This classic spice adds a subtle warmth that elevates the whole dish.

Step 4: Add the Cheese

Remove the sauce from heat and stir in 3/4 cup each of Gruyere and cheddar and 1/4 cup Parmesan, stirring until the cheese melts into a gorgeously creamy sauce. Setting aside some cheese at this stage is important for the topping — it ensures a fabulous golden crust later.

Step 5: Combine Squash and Sauce, Then Bake

Now comes the fun part: shred the roasted spaghetti squash with a fork into strands and gently fold them into the cheese sauce. Once combined, pour the spaghetti squash mixture into a greased 9×13 inch baking dish, spreading it out evenly. This step is where all your hard work comes together, making sure every bite will be gooey and cheesy all the way through. In a separate bowl, mix the reserved cheeses with panko breadcrumbs and sprinkle the mixture evenly on top. Pop your dish into the oven and bake for 20-25 minutes until the topping is golden and bubbly.

How to Serve Pour the spaghetti squash mixture into a greased 9×13 inch baking dish

Garnishes

A sprinkle of fresh chopped parsley adds a lovely pop of color and brightness that balances the richness of the dish beautifully. You can also consider a light drizzle of good olive oil or a pinch of crushed red pepper flakes if you like a touch of heat.

Side Dishes

This au gratin pairs wonderfully with light, vibrant sides. Try a crisp green salad with lemon vinaigrette for freshness or some roasted asparagus for a complementary vegetal touch. If you want to keep things hearty, warm crusty bread is always a winner to mop up any cheesy sauce left on your plate.

Creative Ways to Present

If you want to impress at a dinner party, consider serving individual portions baked in ramekins for an elegant touch. Alternatively, scoop this cheesy delight into hollowed-out roasted bell peppers or portobello caps for a fun presentation twist that’s as inviting as it is tasty.

Make Ahead and Storage

Storing Leftovers

Spaghetti Squash Au Gratin keeps beautifully in an airtight container in the refrigerator for up to 3-4 days. The flavors actually deepen with time, making leftovers a delicious next-day treat.

Freezing

This dish freezes well if you want to prep ahead. After baking, let it cool completely, then cover tightly with foil and store it in the freezer for up to 2 months. When you’re ready to enjoy, thaw overnight in the fridge.

Reheating

To reheat, warm leftovers in a preheated oven at 350°F (175°C) until hot and bubbly, about 15-20 minutes. This brings back that delightful crispy topping and creamy center better than a microwave ever could.

FAQs

Can I use a different type of squash?

Spaghetti squash is unique because of its stringy texture, which mimics pasta. While you could try butternut or acorn squash, the texture and outcome will be quite different — less “spaghetti-like” but still tasty.

What if I don’t have Gruyere cheese?

You can substitute Gruyere with Swiss cheese or even mozzarella for a different melt and flavor. Gruyere brings a slightly nutty richness, but the recipe is flexible to accommodate what you have on hand.

Is this dish gluten-free?

The traditional recipe uses all-purpose flour and panko breadcrumbs, which contain gluten. For a gluten-free version, use a gluten-free flour blend for the roux and gluten-free breadcrumbs in the topping.

Can I make this vegan or dairy-free?

To veganize this dish, swap the butter for plant-based margarine, milk for unsweetened plant milk, and use vegan cheese alternatives. The texture won’t be quite the same but can still be delicious and comforting.

How do I know when the squash is done roasting?

Roasted spaghetti squash is done when it can be easily pierced with a fork and the flesh twists into strands easily when shredded. The timing may vary slightly depending on the squash size.

Final Thoughts

This Spaghetti Squash Au Gratin recipe is a true crowd-pleaser that feels like a cozy hug from the inside out. Don’t hesitate to pour the spaghetti squash mixture into a greased 9×13 inch baking dish and watch as simple ingredients transform into something spectacular. Whether you’re feeding family or entertaining guests, this dish has all the charm, warmth, and comfort to become a forever favorite on your dinner table.

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