If you’ve ever longed for a cozy, cheesy side that feels indulgent yet sneaky-healthy, this Creamy Spaghetti Squash Au Gratin Recipe is about to become your new best friend. Imagine tender, tender strands of roasted spaghetti squash enrobed in a velvety, cheesy sauce that’s perfectly seasoned and baked to bubbly, golden perfection. This dish is a delightful twist on classic au gratin, swapping out potatoes for light, naturally gluten-free spaghetti squash so you get all the comfort without the heaviness. From its inviting aroma to the melt-in-your-mouth texture, every bite is a delicious celebration of fresh ingredients coming together in pure harmony.
Ingredients You’ll Need
Simple, essential ingredients are what make this Creamy Spaghetti Squash Au Gratin Recipe truly shine. Each one brings crucial elements to the table: luscious creaminess, just the right amount of savory bite, and a satisfying texture that invites second and third helpings.
- 1 medium spaghetti squash (about 3 pounds): The star base that roasts to tender, pasta-like strands with a subtle sweetness.
- 1 tablespoon olive oil: Helps roast the squash to perfection and adds a fragrant richness.
- 2 tablespoons unsalted butter: Builds the creamy roux that forms the glistening sauce.
- 1 small yellow onion (finely chopped): Adds gentle sweetness and depth when sautéed.
- 2 cloves garlic (minced): Imparts aromatic warmth that enhances every flavor.
- 1 tablespoon all-purpose flour: Thickens the sauce into a luscious consistency (gluten-free flour works beautifully too).
- 3/4 cup whole milk: Creates the smooth, silky base of the creamy sauce.
- 1/2 cup sour cream: Brings tang and richness, balancing the cheddar’s sharpness.
- 1/2 teaspoon salt: Highlights all the flavors just right.
- 1/4 teaspoon black pepper: Adds subtle heat and complexity.
- 1/4 teaspoon ground nutmeg: A classic au gratin touch that adds warmth and a hint of earthiness.
- 1 cup shredded sharp cheddar cheese: The melty, gooey heart of this dish with bold flavor.
- 1/4 cup grated Parmesan cheese: Provides a golden, crispy topping with nutty undertones.
- 2 tablespoons chopped fresh parsley (for garnish): Adds fresh color and a little brightness on top.
How to Make Creamy Spaghetti Squash Au Gratin Recipe
Step 1: Roast the Spaghetti Squash
Start by preheating your oven to 400°F (200°C). Carefully slice the spaghetti squash in half lengthwise and scoop out all the seeds—that’s an important step for clean, strand-like flesh. Drizzle the cut sides with olive oil to add flavor and help with caramelization, then place them cut-side down on a baking sheet. Roast for 35 to 40 minutes until the squash is tender and you can easily pierce it with a fork. Let it cool just enough to handle, then use a fork to gently scrape out the flesh into long strands that look just like spaghetti noodles.
Step 2: Make the Creamy Cheese Sauce
While your squash is roasting, melt unsalted butter in a large skillet over medium heat. Add the finely chopped onion and cook until softened and fragrant, around 4 minutes. Toss in the minced garlic and cook for just 30 seconds to avoid burning but release its flavor. Sprinkle the flour evenly over the mixture and whisk constantly for about a minute—this helps cook out any raw flour taste and forms your roux. Slowly whisk in the whole milk, stirring to prevent lumps. Let it bubble and thicken for roughly 3 to 4 minutes until luxuriously smooth.
Step 3: Combine and Season
Take your sauce off the heat and stir in sour cream, salt, black pepper, and the warm hint of nutmeg. Add the sharp cheddar cheese and mix until it melts fully into the creamy base. Fold in the roasted spaghetti squash strands, making sure each strand is saturated with cheesy goodness. This step ensures every bite is bursting with flavor and creaminess.
Step 4: Bake to Golden Perfection
Transfer this dreamy mixture to a greased 2-quart baking dish. Sprinkle the grated Parmesan cheese evenly on top, which will create that signature golden crust au gratin dishes are famous for. Pop it into a 375°F (190°C) oven and bake for about 20 to 25 minutes until the edges bubble and the top turns beautifully golden. Your kitchen will fill with the most irresistible aroma!
How to Serve Creamy Spaghetti Squash Au Gratin Recipe
Garnishes
Freshly chopped parsley is the perfect finishing touch—it adds a pop of color and a fresh herbal note that contrasts the richness of the cheese. You can also sprinkle a little extra Parmesan or a pinch of smoked paprika for a subtle smoky kick.
Side Dishes
This Creamy Spaghetti Squash Au Gratin Recipe pairs wonderfully with grilled chicken, roasted vegetables, or a crisp green salad. The au gratin itself is hearty enough to be a vegetarian main dish or a comforting side for holiday feasts and weeknight dinners alike.
Creative Ways to Present
For a special occasion, serve this dish in individual ramekins, garnished with a sprig of parsley or thyme. You could also stuff the roasted squash shells with the cheesy mixture for a rustic and charming presentation everyone will love.
Make Ahead and Storage
Storing Leftovers
Store any leftovers in an airtight container in the refrigerator for up to 3 days. The flavors actually deepen a bit overnight, making for an even more delicious next-day treat.
Freezing
You can freeze the au gratin before baking or after it has cooled post-baking. Wrap tightly with plastic wrap and aluminum foil or place in a freezer-safe dish for up to 2 months. Thaw overnight in the fridge before reheating.
Reheating
Reheat leftovers gently in a 350°F (175°C) oven for about 15 to 20 minutes until warmed through and bubbly. Cover with foil to prevent the top from browning too much, uncover at the end for a few minutes if you want to refresh the golden crust.
FAQs
Is spaghetti squash really gluten-free?
Yes, spaghetti squash is a naturally gluten-free vegetable, making this au gratin recipe a great option for those avoiding gluten. Just be sure to use gluten-free flour if you’re preparing a gluten-free version.
Can I use a different cheese?
Absolutely! While sharp cheddar and Parmesan give the dish its classic flavor, you can experiment with Gruyère, mozzarella, or even a bit of blue cheese for a more intense twist.
Can I make this ahead of time?
Yes, you can prepare the entire dish up to the baking step and refrigerate it overnight. When ready, just bake as directed, adding a few extra minutes to ensure it’s hot and bubbly.
What if I don’t have sour cream?
Sour cream adds tang and creaminess but can be replaced with Greek yogurt for a similar effect or cream cheese for extra richness, depending on your taste preference.
Is this recipe suitable for meal prep?
Definitely! This creamy spaghetti squash au gratin holds up really well when stored and reheated, making it perfect for preparing lunches or dinners ahead of busy days.
Final Thoughts
This Creamy Spaghetti Squash Au Gratin Recipe is truly one of those comforting dishes that feels like a warm hug on a plate. Whether you’re after a wholesome weeknight side or a show-stopping vegetarian offering for a gathering, it’s a wonderful way to enjoy healthy veggies with unforgettable creaminess and cheese. I encourage you to give it a try—you might just find it becoming a cherished classic in your recipe collection!
Print
Creamy Spaghetti Squash Au Gratin Recipe
- Prep Time: 15 minutes
- Cook Time: 1 hour
- Total Time: 1 hour 15 minutes
- Yield: 6 servings
- Category: Side Dish
- Method: Baking
- Cuisine: American
- Diet: Vegetarian, Gluten Free
Description
A creamy, cheesy spaghetti squash au gratin featuring tender roasted squash strands enveloped in a rich cheddar and sour cream sauce, baked to golden perfection. This low-carb, vegetarian side dish offers a comforting texture and savory flavors ideal for cozy dinners.
Ingredients
Spaghetti Squash
- 1 medium spaghetti squash (about 3 pounds)
- 1 tablespoon olive oil
- 2 tablespoons unsalted butter
Sauce
- 1 small yellow onion, finely chopped
- 2 cloves garlic, minced
- 1 tablespoon all-purpose flour (use gluten-free flour for gluten-free version)
- 3/4 cup whole milk
- 1/2 cup sour cream
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper
- 1/4 teaspoon ground nutmeg
Cheese and Garnish
- 1 cup shredded sharp cheddar cheese
- 1/4 cup grated Parmesan cheese
- 2 tablespoons chopped fresh parsley (for garnish)
Instructions
- Roast the Spaghetti Squash: Preheat your oven to 400°F (200°C). Cut the spaghetti squash in half lengthwise and scoop out all the seeds. Drizzle the cut sides with olive oil and place them face down on a baking sheet. Roast for 35 to 40 minutes until the flesh is tender. Let the squash cool slightly, then use a fork to scrape out the flesh into strands. Set aside.
- Prepare the Sauce Base: In a large skillet over medium heat, melt the butter. Add the finely chopped onion and cook until it becomes soft and translucent, about 4 minutes. Stir in the minced garlic and cook for an additional 30 seconds until fragrant.
- Make the Roux and Cheese Sauce: Sprinkle the flour over the onion and garlic mixture, whisking constantly for 1 minute to make a roux. Gradually whisk in the milk and cook for 3 to 4 minutes until the sauce thickens slightly. Remove the skillet from heat, then stir in the sour cream, salt, black pepper, and ground nutmeg.
- Add Cheese and Combine with Squash: Mix in the shredded sharp cheddar cheese until melted and the sauce is smooth. Fold in the spaghetti squash strands, stirring gently until all strands are well coated with the creamy cheese sauce.
- Bake the Au Gratin: Transfer the squash mixture to a greased 2-quart baking dish. Evenly sprinkle the grated Parmesan cheese on top. Reduce oven temperature to 375°F (190°C) and bake the dish for 20 to 25 minutes until bubbly and golden brown on top.
- Garnish and Serve: Remove the casserole from the oven and let it cool for a few minutes. Garnish with chopped fresh parsley before serving for a fresh pop of color and flavor.
Notes
- You can substitute Greek yogurt for sour cream for a tangier flavor.
- For extra richness, stir in a bit of cream cheese into the sauce.
- Use gluten-free flour to make this dish gluten-free.
- Leftovers reheated gently in the oven retain creamy texture.
