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Spaghetti Squash Au Gratin Recipe

Spaghetti Squash Au Gratin is a healthy and delicious main dish that is not only good for you but also incredibly easy to make. This dish is made with just a few simple ingredients like spaghetti squash, onions, butter, cheddar cheese, salt, and pepper.

Spaghetti Squash Au Gratin Recipe

It has a perfect balance of flavors, with the spaghetti squash being balanced out by the slightly sweet flavor of caramelized onions, the creaminess of the butter, and the sharpness of cheddar cheese.  

Ingredients You’ll Need

  • 1 Spaghetti Squash: look for a squash that is firm and heavy for its size, with dull, not shiny, hard skin. The skin should be hard, not easily punctured by your fingernail
  • 1 Onion: choose a yellow onion for a sweet mild flavor. They’re great for caramelizing
  • Spices and Seasonings: red pepper flakes and garlic powder are great options for this, but feel free to mix and match accordingly to your tastes
  • Sour Cream: this adds a nice creamy texture, feel free to substitute it with plain greek yogurt as well
  • Cheese: cheddar cheese is a great option, but feel free to use whatever cheese you like. Vegan cheese works as well!

Spaghetti Squash Au Gratin Recipe

How to Make Spaghetti Squash Au Gratin

This Spaghetti Squash Au Gratin is a perfect way to enjoy a comforting and satisfying meal while keeping it light and healthy, without spending hours in the kitchen.

  1. This recipe is one of the simplest and quickest you’ll follow! Yet, it results in a satisfying and filling dish. Halve and remove the seeds from your spaghetti squash. Place your halves in a microwave-safe bowl and fill with ¼ inch of water.
  2. Do it one half at a time. Microwave for 12 minutes. Remove from the microwave and use a fork to shred your spaghetti squash into strands and set aside. Cut up your onions. Heat the butter in a medium-sized skillet until melted.
  3. Add the onions, red pepper flakes, garlic powder, salt, and pepper to taste. Cook the onions until brown and caramelized. In a bowl, mix together the spaghetti squash, onions, half of the cheese, and all of the sour cream.
  4. Pour this mixture into a baking dish and top off with the rest of the cheese. Bake in the oven for 20 minutes. Then broil it for 3-5 minutes until the cheese on top is slightly brown! Remove from the oven and enjoy!

Spaghetti Squash Au Gratin Recipe

Tips for Cooking Spaghetti Squash

  • Let cool after cooking in the microwave for easier handling.
  • Gently scrape to create long, spaghetti-like strands
  • You can poke some holes in the squash before microwaving it to allow the steam to escape and prevent the squash from bursting.
  • Cook time for spaghetti squash depends on size so check periodically between 8-12 minutes to make sure it doesn’t overcook.

Make Ahead and Storage Tips

This dish is great to make ahead of time in bulk as meal prep for your week since it is very simple and takes little time to make. You can store this dish in the refrigerator for 3-5 days in an airtight container.

You can freeze this dish in an airtight container for up to 2 weeks!

To reheat: Place inside a 375 F for 10 minutes and then broil for 2 minutes with some extra cheese on top.

Spaghetti Squash Au Gratin Recipe

Spaghetti Squash Au Gratin Recipe

Yield: 10
Prep Time: 10 minutes
Cook Time: 25 minutes
Total Time: 35 minutes

Spaghetti Squash Au Gratin is a healthy and delicious main dish that is not only good for you but also incredibly easy to make.


  • 1 medium sized spaghetti squash
  • 1 medium yellow onion, sliced thinly
  • 3 tablespoons butter
  • 1 teaspoon red pepper flakes
  • 1 teaspoon garlic powder
  • Salt and pepper to taste
  • 1 cup sour cream
  • 1 cup freshly shredded sharp cheddar cheese


  1. Preheat your oven to 375F.

    Preparing the Spaghetti Squash:
  2. Cut in half and remove the seeds
  3. Place the halves in a microwave-safe dish and add water to the dish, about ¼ inch high Cover the dish loosely with plastic wrap and microwave the halved spaghetti squash for 8-12 minutes, checking periodically for doneness

  4. Let cool until it’s safe to handle to the touch Use a fork to gently scrape the squash to separate it from its skin and create strands

  5. Place the strands into a bowl and set aside

    Preparing the Onions:
  1. Melt the butter in a medium-sized skillet over medium heat.

  2. Once the butter is melted add in your onions and seasonings

  3. Cook the onions until lightly browned

    Putting it together:
  1. In a medium-sized bowl, Mix together the onions spaghetti squash, sour cream, and half of the cheese. Pour into a greased oven-safe dish

  2. Top it off with the rest of the cheese

    Spaghetti Squash Au Gratin Recipe
  3. Bake in the oven for 20 minutes
  4. After 20 minutes broil for 2-5 minutes until golden brown on top, Remove, serve, and enjoy the best Spaghetti Squash Au Gratin ever!

    Spaghetti Squash Au Gratin Recipe
Nutrition Information:

Amount Per Serving: Calories: 115Total Fat: 5gCarbohydrates: 11gProtein: 8g

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