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
Scale
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.
