Spaghetti Squash Au Gratin (Printable)

Tender roasted squash strands blended with sour cream, nutmeg, and melted cheeses, then baked until bubbly and golden.

# What You Need:

→ Vegetables

01 - 1 large spaghetti squash (about 3 lbs)
02 - 2 tablespoons olive oil
03 - 1 small yellow onion, finely chopped
04 - 2 cloves garlic, minced

→ Dairy & Cheese

05 - 1 cup shredded Gruyère cheese
06 - 1/2 cup grated Parmesan cheese
07 - 1/2 cup sour cream
08 - 2 tablespoons unsalted butter
09 - 1/4 cup whole or 2% milk

→ Spices & Seasoning

10 - 1/2 teaspoon salt
11 - 1/4 teaspoon ground black pepper
12 - 1/4 teaspoon ground nutmeg
13 - 1 tablespoon chopped fresh parsley (optional, for garnish)

# How-To Steps:

01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
02 - Cut the spaghetti squash in half lengthwise and scoop out the seeds. Drizzle the cut sides with 1 tablespoon olive oil and sprinkle with salt and pepper.
03 - Place the squash halves cut-side down on the prepared baking sheet. Roast for 35–40 minutes, until the flesh is tender and easily shredded with a fork.
04 - While the squash is roasting, heat the remaining 1 tablespoon olive oil and the butter in a skillet over medium heat. Add the onion and cook until soft and translucent, about 5 minutes. Add the garlic and cook for 1 minute more.
05 - Remove the squash from the oven. Allow to cool slightly, then use a fork to scrape the flesh into spaghetti-like strands. Place the strands in a large mixing bowl.
06 - Add the cooked onion and garlic, sour cream, milk, half the Gruyère, half the Parmesan, nutmeg, salt, and pepper to the bowl. Mix until well combined.
07 - Transfer the mixture to a greased 2-quart baking dish. Top with the remaining Gruyère and Parmesan.
08 - Reduce oven temperature to 375°F. Bake for 20–25 minutes, until the top is golden and bubbly.
09 - Garnish with chopped parsley before serving, if desired.

# Helpful Tips:

01 -
  • The way the cheese sauce clings to those tender squash strands makes you forget you're eating vegetables
  • Its the kind of dish that makes guests ask for seconds before they even realize its low carb
02 -
  • Overcooking the squash before mixing makes it watery, so pull it when it's just tender
  • Room temperature sour cream incorporates more smoothly into the sauce
03 -
  • Use a box grater to shred your own cheese instead of buying pre shredded for better melting
  • Let the dish rest 5 minutes before serving so the sauce sets slightly