Creamy Spaghetti Squash Au Gratin is a cozy, cheesy, and low-carb twist on a classic comfort food. With roasted spaghetti squash, sautéed onions, garlic, sour cream, and sharp cheddar, it’s a dish that satisfies without the heaviness of traditional gratins. Perfect as a side or a vegetarian main, this recipe brings indulgent flavor while keeping things light and wholesome.

Creamy Spaghetti Squash Au Gratin

Why You’ll Love This Recipe

I love how this dish delivers all the creamy, cheesy satisfaction of a traditional gratin, but with a healthier, low-carb base. The spaghetti squash provides a tender, noodle-like texture that pairs beautifully with the rich, savory sauce. It’s a versatile recipe that’s perfect for family dinners, potlucks, or meal prep. Plus, it’s gluten-free and can easily be adapted to suit various dietary needs.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

1 medium spaghetti squash (about 2–3 lbs)
2 tablespoons butter
1 small onion, finely chopped
2 cloves garlic, minced
1/2 cup sour cream
1 1/2 cups shredded sharp Cheddar cheese
Salt and pepper, to taste
Optional: chopped parsley for garnish

Directions

Cook the Spaghetti Squash: Preheat the oven to 400°F (200°C). Carefully slice the spaghetti squash in half lengthwise and scoop out the seeds. Place both halves cut-side down on a baking sheet lined with parchment or foil. Roast for about 30–40 minutes, or until the flesh is tender and easily shredded with a fork. Let it cool slightly, then use a fork to scrape the inside into spaghetti-like strands.
Sauté the Aromatics: While the squash cools, melt the butter in a large skillet over medium heat. Add the chopped onion and cook until soft and translucent, about 5 minutes. Stir in the minced garlic and cook for another 30 seconds until fragrant.
Mix the Filling: Add the shredded spaghetti squash to the skillet and stir everything together. Reduce the heat to low and mix in the sour cream, then season with salt and pepper to taste. Stir in 1 cup of shredded Cheddar cheese, mixing until the cheese is melted and the mixture is creamy.
Bake It Up: Preheat your oven’s broiler. Transfer the creamy squash mixture into a greased baking dish (8×8 or similar). Sprinkle the remaining 1/2 cup of Cheddar cheese evenly over the top. Broil for 2 to 4 minutes, or until the cheese is bubbly and golden brown. Keep a close eye on it to prevent burning.
Garnish and Serve: Sprinkle with fresh chopped parsley if desired. Serve warm as a side dish or enjoy as a main course with a salad or protein.

Servings and Timing

Servings: 6
Prep Time: 15 minutes
Cook Time: 40 minutes
Total Time: 55 minutes

Variations

Cheese Options: Swap sharp Cheddar for Gruyère, Monterey Jack, or a blend of your favorite cheeses for a different flavor profile.
Spice It Up: Add a pinch of red pepper flakes or diced jalapeños for some heat.
Herbaceous Twist: Mix in fresh herbs like thyme, rosemary, or basil to enhance the flavor.

Storage/Reheating

Storage: Store leftovers in an airtight container in the refrigerator for up to 3 days.
Reheating: Reheat individual portions in the microwave for 1–2 minutes, or warm the entire dish in a 350°F (175°C) oven until heated through.

FAQs

How do I prevent the gratin from becoming watery?

Ensure you drain any excess moisture from the cooked spaghetti squash before mixing it with the other ingredients. Letting the squash sit in a colander for a few minutes can help remove additional water.

Can I make this dish ahead of time?

Yes, you can prepare the gratin up to the point of baking, then cover and refrigerate it for up to 24 hours. When ready to serve, bake as directed, adding a few extra minutes to account for the chilled dish.

Is there a dairy-free alternative for this recipe?

You can substitute the butter with a plant-based alternative, use dairy-free sour cream, and opt for vegan cheese shreds to make this dish dairy-free.

What can I serve with this gratin?

This dish pairs well with a fresh green salad, roasted vegetables, or as a side to grilled meats like chicken or steak.

Can I freeze the leftovers?

While it’s possible to freeze the gratin, the texture may change upon reheating, becoming slightly watery. If you choose to freeze it, wrap it tightly and consume within a month for best results.

Conclusion

Creamy Spaghetti Squash Au Gratin is a delightful blend of comfort and nutrition. Its rich, cheesy flavor satisfies cravings while keeping things light and wholesome. Whether you’re looking for a new side dish or a vegetarian main, this recipe is sure to become a favorite in your kitchen.