If you’re looking for a cozy, crave-worthy side dish that will steal the spotlight at any table, Creamy Spaghetti Squash Au Gratin is about to become your new obsession. With its silky squash strands, rich cheesy sauce, and a golden, bubbling top, this casserole transforms a humble vegetable into pure comfort food. Whether you’re cutting carbs, feeding vegetarians, or just want something irresistibly creamy and flavorful, this recipe checks every box—and then some!

Creamy Spaghetti Squash Au Gratin Recipe - Recipe Image

Ingredients You’ll Need

The magic of Creamy Spaghetti Squash Au Gratin begins with a handful of simple, wholesome ingredients. Each one brings something special—whether it’s creaminess, a burst of savory flavor, or that essential cheesy finish. Here’s what you’ll need and why each is a must:

Spaghetti Squash: This humble squash transforms into tender, noodle-like strands that soak up all the cheesy goodness.
Olive Oil: Just a touch helps roast the squash and sauté the aromatics for a deeper, richer flavor.
Onion: Finely chopped onion adds sweet, mellow depth and a perfect savoriness to the dish.
Garlic: A couple of cloves infuse the gratin with unmistakable, aromatic warmth.
Sour Cream: This is the secret to the sauce’s creamy, tangy base that sets the dish apart.
Parmesan Cheese: Adds nutty, salty sharpness and helps create that signature gratin crust.
Sharp Cheddar Cheese: Melts like a dream, bringing bold flavor and serious gooeyness.
Dried Thyme: A sprinkle of thyme lifts everything with herby freshness.
Salt: Enhances every flavor and ties the whole dish together.
Black Pepper: Adds a gentle, balancing heat without overpowering.
Breadcrumbs (optional): For an extra-crispy, golden topping that’s pure comfort—skip for low-carb!
Butter (optional): Melted with breadcrumbs, it creates that irresistible, buttery crunch on top.

How to Make Creamy Spaghetti Squash Au Gratin

Step 1: Roast the Spaghetti Squash

Start by preheating your oven to 400°F. Carefully cut the spaghetti squash in half lengthwise and scoop out the seeds. Place the halves cut-side down on a parchment-lined baking sheet. Roasting the squash this way ensures it becomes perfectly tender and easy to shred into those signature strands. Bake for 35 to 40 minutes, until the flesh yields easily to a fork.

Step 2: Sauté the Aromatics

While the squash roasts, heat your olive oil in a skillet over medium heat. Add the finely chopped onion and cook until it’s soft, translucent, and just starting to caramelize—about 5 minutes. Toss in the minced garlic for one minute more. This step builds a savory backbone for your Creamy Spaghetti Squash Au Gratin, infusing every bite with sweet and aromatic depth.

Step 3: Shred and Mix

Once the roasted squash is cool enough to handle, grab a fork and gently scrape the flesh into strands. Transfer these golden noodles into a large bowl. Add your cooked onions and garlic, sour cream, Parmesan, cheddar, thyme, salt, and pepper. Stir everything together until the mixture is creamy, well blended, and positively mouthwatering.

Step 4: Assemble and Top

Spoon the squash mixture into a greased 9×9-inch baking dish, spreading it out evenly. If you’re craving that classic au gratin crunch, melt the butter and toss it with the breadcrumbs. Sprinkle this mixture over the top for a golden, crispy finish. This step is optional, but trust me—it’s worth it.

Step 5: Bake to Perfection

Pop the baking dish into your preheated oven. Bake for 20 minutes, or until the Creamy Spaghetti Squash Au Gratin is bubbling and the top is gorgeously golden brown. Let it cool for a few minutes before serving so the flavors can settle and the texture gets extra creamy.

How to Serve Creamy Spaghetti Squash Au Gratin

Garnishes

A sprinkle of freshly chopped parsley or chives adds a bright pop of color and a fresh, herby note that balances the rich, cheesy interior. For a gourmet touch, try a dusting of extra Parmesan or a pinch of smoked paprika before serving.

Side Dishes

Creamy Spaghetti Squash Au Gratin is a versatile side that pairs beautifully with roasted chicken, steak, or a simple green salad. For a vegetarian spread, serve it alongside sautéed greens or a hearty bean dish. Its creamy texture and savory flavor make it a star next to almost anything.

Creative Ways to Present

For a fun twist, serve individual portions in small ramekins or hollowed-out squash shells for an elegant dinner party look. You can even use it as a filling for stuffed bell peppers or mushrooms, turning leftovers into a whole new meal.

Make Ahead and Storage

Storing Leftovers

Leftover Creamy Spaghetti Squash Au Gratin keeps very well in the fridge. Simply cover the baking dish tightly or transfer portions to an airtight container and store for up to 3 days. The flavors deepen as it sits, making leftovers especially delicious.

Freezing

This dish can be frozen, though the texture may change slightly after thawing. Let the gratin cool completely, then wrap tightly in plastic and foil, or use a freezer-safe container. Freeze for up to 2 months. Thaw overnight in the fridge before reheating.

Reheating

To reheat, bake the gratin (covered with foil) at 350°F until warmed through, about 20 minutes. For individual portions, the microwave works well—just heat in short bursts and stir in between to maintain the creamy texture.

FAQs

Is Creamy Spaghetti Squash Au Gratin gluten-free?

Yes! Simply omit the breadcrumb topping or use gluten-free breadcrumbs, and the entire dish is naturally gluten-free. The spaghetti squash and cheesy sauce are both safe for gluten-free diets.

Can I make it ahead of time?

Absolutely. You can assemble the gratin up to a day ahead, cover, and refrigerate. When ready to serve, bake as directed, adding a few extra minutes if it’s coming straight from the fridge.

What’s the best cheese for this recipe?

A combination of sharp cheddar and Parmesan is classic for Creamy Spaghetti Squash Au Gratin, giving both creaminess and depth. Feel free to experiment with Gruyère or Swiss for a different flavor profile.

How can I add more protein?

Mix in cooked bacon, shredded chicken, or even sautéed mushrooms for extra protein and heartiness. These additions blend beautifully with the creamy, cheesy base.

Can I make this dairy-free?

You can! Use your favorite dairy-free cheese and sour cream substitutes. The resulting gratin will still be rich and satisfying, though the flavor and texture may vary slightly from the classic version.

Final Thoughts

If you’ve never tried Creamy Spaghetti Squash Au Gratin, now’s the perfect time to fall in love with this comforting, crowd-pleasing dish. It’s easy enough for a weeknight but so delicious you’ll want to share it at every gathering. Trust me—your table (and your taste buds) will thank you!

Creamy Spaghetti Squash Au Gratin Recipe

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4.5 from 13 reviews

Author: admin
Total Time: 1 hour 15 minutes
Yield: 6 servings 1x
Diet: Vegetarian

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Description

This Creamy Spaghetti Squash Au Gratin is a delicious and comforting low-carb alternative to traditional potato gratin. Roasted spaghetti squash is combined with sautéed onions, garlic, sour cream, and a blend of Parmesan and sharp cheddar cheeses, then baked until bubbly and golden. It’s perfect as a hearty side or a light vegetarian main dish.

Ingredients

Scale

Main Ingredients

1 medium spaghetti squash (about 3 lbs)
1 tablespoon olive oil
1 small onion, finely chopped
2 cloves garlic, minced
1/2 cup sour cream
1/2 cup shredded Parmesan cheese
1/2 cup shredded sharp cheddar cheese
1/2 teaspoon dried thyme
1/4 teaspoon salt
1/4 teaspoon black pepper

Optional Topping

1/4 cup breadcrumbs (optional, for topping)
1 tablespoon butter (optional, for topping)

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Instructions

Roast the Spaghetti Squash: Preheat the oven to 400°F. Cut the spaghetti squash in half lengthwise and remove the seeds. Place the halves cut-side down on a parchment-lined baking sheet. Roast for 35 to 40 minutes until the flesh is tender and can be shredded easily with a fork.
Sauté Onion and Garlic: While the squash is roasting, heat olive oil in a skillet over medium heat. Add the finely chopped onion and cook until soft and translucent, about 5 minutes. Add the minced garlic and cook for an additional 1 minute. Remove from heat.
Prepare the Squash Strands: After the squash cools enough to handle, use a fork to scrape the flesh into strands into a large mixing bowl.
Combine Ingredients: Add the sautéed onion and garlic, sour cream, shredded Parmesan and cheddar cheeses, dried thyme, salt, and black pepper to the squash strands. Stir gently until everything is well combined.
Assemble in Baking Dish: Transfer the mixture to a greased 9×9 inch baking dish, spreading it evenly.
Add Topping (Optional): If using toppings, melt the butter and stir it together with the breadcrumbs. Sprinkle this mixture evenly over the top.
Bake: Place the dish in the oven and bake for 20 minutes, or until the top is bubbly and golden brown.
Serve: Allow the gratin to cool slightly before serving warm.

Notes

To keep this dish low-carb, omit breadcrumbs or substitute with crushed pork rinds for the topping.
For added flavor, mix in cooked bacon or fresh spinach with the squash mixture before baking.
This recipe works well as a hearty side dish or a light vegetarian main course.

Prep Time: 15 minutes
Cook Time: 60 minutes
Category: Side Dish
Method: Baking
Cuisine: American