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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.

Ingredients

Scale

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

Find it online: https://zestywithzane.com/spaghetti-squash-au-gratin-recipe/