Spaghetti Squash Au Gratin Recipe

Introduction

This Spaghetti Squash Au Gratin is a comforting and elegant twist on a classic dish. Creamy cheese sauce coats tender strands of spaghetti squash, then it’s baked to golden perfection. It’s a delicious, lighter alternative to traditional potato gratin that’s perfect for any occasion.

Ingredients

• 1 large spaghetti squash (about 3-4 pounds)
• 4 tablespoons unsalted butter, divided
• 1 medium yellow onion, finely chopped
• 2 cloves garlic, minced
• 4 tablespoons all-purpose flour
• 3 cups whole milk
• 1/2 teaspoon salt, plus more to taste
• 1/4 teaspoon black pepper, plus more to taste
• 1/4 teaspoon nutmeg
• 1 cup grated Gruyere cheese, divided
• 1 cup grated sharp cheddar cheese, divided
• 1/2 cup grated Parmesan cheese, divided
• 1/4 cup panko breadcrumbs
• 2 tablespoons chopped fresh parsley, for garnish (optional)

Instructions

1. Step 1: Preheat the oven to 400°F (200°C). Cut the spaghetti squash in half lengthwise and scoop out the seeds. Place the halves cut-side down on a baking sheet lined with parchment paper. Roast for 35-45 minutes, until the flesh is tender and easily shredded with a fork.
2. Step 2: While the squash roasts, melt 2 tablespoons of butter in a large skillet over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes. Add the minced garlic and cook for another 1 minute until fragrant.
3. Step 3: Sprinkle the flour over the onion and garlic mixture and whisk continuously for 2 minutes to form a roux. Slowly add the milk, whisking constantly to avoid lumps. Continue to cook until the sauce thickens, about 5-7 minutes.
4. Step 4: Stir in salt, black pepper, nutmeg, 1/2 cup Gruyere, 1/2 cup cheddar, and 1/4 cup Parmesan cheese until melted and smooth. Adjust seasoning to taste.
5. Step 5: Remove the squash from the oven and let cool slightly. Using a fork, shred the flesh of the squash into spaghetti-like strands, leaving the shell intact for serving if desired.
6. Step 6: Combine the shredded squash with the cheese sauce in a large bowl and mix gently to coat evenly.
7. Step 7: Butter a baking dish or use the reserved squash shells. Transfer the squash and sauce mixture into the dish and spread evenly.
8. Step 8: In a small bowl, mix the remaining 2 tablespoons butter (melted) with panko breadcrumbs, remaining Gruyere, cheddar, and Parmesan cheeses. Sprinkle this topping evenly over the squash mixture.
9. Step 9: Bake in the oven at 375°F (190°C) for 20-25 minutes until the topping is golden brown and bubbling.
10. Step 10: Remove from oven and let cool for a few minutes. Garnish with chopped fresh parsley if desired before serving.

Tips & Variations

• For a richer sauce, substitute half of the milk with heavy cream.
• Add cooked bacon or sautéed mushrooms for extra flavor and texture.
• Use gluten-free flour if you need a gluten-free version.
• Try different cheeses like Fontina or mozzarella for variation.

Storage

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven at 350°F (175°C) until warmed through to maintain the crispy topping. Avoid microwaving to keep texture intact.

How to Serve

Serve this delicious recipe with your favorite sides.

FAQs

Can I prepare this dish ahead of time?

Yes, you can assemble the dish a day ahead and keep it covered in the refrigerator. Bake it fresh before serving to ensure the topping stays crisp and the flavors are at their best.

What if I don’t have Gruyere cheese?

Gruyere adds a nutty flavor, but you can substitute with Swiss cheese or a mild white cheddar if you don’t have it on hand. The dish will still be delicious!

Spaghetti Squash Au Gratin Recipe

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★★★★★

4.9 from 52 reviews

This Spaghetti Squash Au Gratin is a comforting, creamy casserole that transforms tender, roasted spaghetti squash strands into a cheesy, golden, gratin dish. Layered with a rich béchamel sauce infused with garlic, onions, Gruyere, cheddar, and Parmesan cheeses, then topped with crunchy panko breadcrumbs, this recipe offers a delicious low-carb twist on classic au gratin potatoes. Perfect as a side or a vegetarian main, it celebrates the natural sweetness and texture of spaghetti squash with a decadent, cheesy crust.

• Author: Zane
• Prep Time: 15 minutes
• Cook Time: 75 minutes
• Total Time: 90 minutes
• Yield: 6 servings 1x
• Category: Side Dish
• Method: Baking
• Cuisine: American
• Diet: Vegetarian

Ingredients

Scale 1x2x3x

Main Ingredients

• 1 large spaghetti squash (about 3–4 pounds)
• 4 tablespoons unsalted butter, divided
• 1 medium yellow onion, finely chopped
• 2 cloves garlic, minced
• 4 tablespoons all-purpose flour
• 3 cups whole milk
• 1/2 teaspoon salt, plus more to taste
• 1/4 teaspoon black pepper, plus more to taste
• 1/4 teaspoon nutmeg

Cheeses and Topping

• 1 cup grated Gruyere cheese, divided
• 1 cup grated sharp cheddar cheese, divided
• 1/2 cup grated Parmesan cheese, divided
• 1/4 cup panko breadcrumbs
• 2 tablespoons chopped fresh parsley, for garnish (optional)

Instructions

1. Prepare the Spaghetti Squash: Preheat your oven to 400°F (200°C). Cut the spaghetti squash in half lengthwise and scoop out the seeds. Place the halves cut-side down on a baking sheet lined with parchment paper or foil. Roast for about 40-50 minutes until the flesh is tender and easily shredded with a fork. Remove from oven and let cool slightly. Use a fork to scrape the squash strands into a bowl and set aside.
2. Make the Béchamel Sauce: In a large skillet or saucepan over medium heat, melt 2 tablespoons of butter. Add the finely chopped onion and cook, stirring occasionally, until softened and translucent, about 5-7 minutes. Add minced garlic and cook for an additional 1 minute until fragrant.
3. Thicken the Sauce: Sprinkle the flour over the onion and garlic mixture, stirring constantly to create a roux. Cook this for 2-3 minutes without browning to eliminate the raw flour taste. Gradually whisk in the whole milk, continuing to whisk until the sauce thickens, about 5-7 minutes. Ensure there are no lumps.
4. Season and Add Spices: Stir in salt, black pepper, and nutmeg. Taste and adjust seasoning as needed to bring out a balanced flavor.
5. Add the Cheese: Remove the sauce from heat and stir in half of the Gruyere, cheddar, and Parmesan cheeses until melted and smooth. This creates a rich, creamy cheese sauce ready to coat the squash strands.
6. Combine and Assemble: Gently fold the prepared spaghetti squash strands into the cheese sauce, making sure the strands are evenly coated. Transfer this mixture into a buttered 9×13 inch baking dish, spreading it evenly.
7. Prepare the Topping: In a small bowl, combine the remaining cheeses with panko breadcrumbs. Melt the remaining 2 tablespoons of butter and drizzle over the breadcrumb-cheese mixture to help it brown beautifully.
8. Bake: Sprinkle the breadcrumb and cheese mixture evenly over the top of the squash casserole. Bake in the preheated oven at 400°F (200°C) for 20-25 minutes, or until the topping is golden brown and crisp, and the casserole is bubbly around the edges.
9. Garnish and Serve: Remove from the oven and let rest for 5-10 minutes. Sprinkle chopped fresh parsley over the top for a pop of color and freshness, if desired. Serve warm as a delicious side dish or vegetarian main course.

Notes

• Spaghetti squash size can vary; adjust roasting time accordingly to ensure tender flesh.
• You can substitute whole milk with 2% milk, but the sauce will be less rich.
• For a gluten-free version, use gluten-free flour and breadcrumbs.
• Gruyere cheese adds a nice nutty flavor, but you can substitute with Swiss cheese if needed.
• Make ahead: You can prepare the squash and béchamel sauce in advance, assemble, then refrigerate before baking.
• Leftovers keep well in the refrigerator for up to 3 days and reheat nicely in the oven or microwave.

Keywords: spaghetti squash, au gratin, cheesy casserole, vegetable side dish, vegetarian, comfort food