Caramelized Onion Spaghetti Squash is a simple yet flavorful dish that transforms wholesome ingredients into a cozy, low-carb dinner. The sweet, buttery onions pair beautifully with tender spaghetti squash strands, creating a meal that feels indulgent without the extra carbs.
This recipe has become a favorite in my kitchen, much like my Stuffed Spaghetti Squash with Broccoli, Sausage & Cheddar. It’s easy to prepare, family-friendly, and full of rich, savory flavors—perfect for busy weeknights or when you want something both healthy and satisfying.
Why You’ll Love This Caramelized Onion Spaghetti Squash
- Quick and easy to prepare, perfect for busy weeknights.
- Low-carb and vegetarian, making it a healthy choice for everyone.
- The sweet, rich flavor of caramelized onions elevates the dish.
- Versatile—add your favorite veggies or proteins for a personal touch.
- Great for meal prep; it reheats beautifully for leftovers.
Caramelized Onion Spaghetti Squash
- Total Time: 55 minutes
- Yield: 4 servings
- Diet: Vegetarian
Description
A delicious and easy recipe for caramelized onion spaghetti squash, perfect for a low-carb vegetarian dinner.
Ingredients
- 1 2-3 lb. spaghetti squash
- 1/4 cup olive oil
- 2 tbsp butter (dairy-free option available)
- 2 medium yellow onions, peeled and sliced into longer strips
- 1 1/2 cup mushrooms
- 1 cup kale
- 1/4 tsp rosemary (fresh or dried)
- Salt and pepper to taste
- Optional: sprinkle of parmesan cheese
Instructions
- Preheat the oven to 400°F (200°C).
- Cut the spaghetti squash in half lengthwise and scoop out the seeds.
- Drizzle olive oil over the cut sides and season with salt and pepper.
- Place the squash cut side down on a baking sheet and roast for 30-40 minutes until tender.
- While the squash is roasting, heat butter and olive oil in a large skillet over medium heat.
- Add the sliced onions and cook until caramelized, about 15-20 minutes.
- Add mushrooms and kale to the skillet and cook until softened.
- Once the squash is done, scrape the flesh with a fork to create spaghetti-like strands.
- Combine the spaghetti squash with the caramelized onion mixture and toss to combine.
- Serve warm, topped with a sprinkle of parmesan cheese if desired.
Notes
- For a vegan option, omit the parmesan cheese.
- Feel free to add other vegetables or proteins as desired.
- This dish can be made ahead of time and reheated.
- Prep Time: 15 minutes
- Cook Time: 40 minutes
- Category: Main Dish
- Method: Roasting and Sautéing
- Cuisine: American
Ingredients for Caramelized Onion Spaghetti Squash
Gathering the right ingredients is key to making a delightful Caramelized Onion Spaghetti Squash. Here’s what you’ll need:
- Spaghetti Squash: This is the star of the dish! Its unique texture mimics pasta, making it a fantastic low-carb alternative.
- Olive Oil: A drizzle of this healthy fat adds richness and helps with roasting. You can also use avocado oil for a different flavor.
- Butter: Adds a creamy depth to the caramelized onions. For a dairy-free option, simply swap it out for more olive oil.
- Yellow Onions: These are perfect for caramelizing, bringing out a sweet, rich flavor that complements the squash beautifully.
- Mushrooms: I love using mushrooms for their earthy taste and meaty texture. They add a wonderful umami flavor to the dish.
- Kale: This leafy green not only boosts nutrition but also adds a lovely color and texture. Feel free to substitute with spinach if you prefer.
- Rosemary: A hint of this herb elevates the dish with its aromatic flavor. Fresh or dried works well!
- Salt and Pepper: Essential for seasoning, these simple ingredients enhance all the flavors in the dish.
- Optional: Parmesan Cheese: A sprinkle of this cheese adds a savory finish. For a vegan option, simply leave it out.
For exact measurements, check the bottom of the article where you can find everything listed for easy printing!
How to Make Caramelized Onion Spaghetti Squash
Now that you have your ingredients ready, let’s dive into the steps for making this delightful Caramelized Onion Spaghetti Squash. Each step is simple, and I promise you’ll feel like a kitchen pro by the end!
Step 1: Preheat the Oven
First things first, preheat your oven to 400°F (200°C). Preheating is crucial because it ensures even cooking. You want that spaghetti squash to roast perfectly, creating tender strands that are just waiting to soak up all those delicious flavors.
Step 2: Prepare the Spaghetti Squash
Next, grab your spaghetti squash. Carefully cut it in half lengthwise. Use a sturdy knife and take your time—safety first! Once halved, scoop out the seeds with a spoon. This step is essential for achieving that perfect texture later on.
Step 3: Season the Squash
Now it’s time to season! Drizzle olive oil over the cut sides of the squash. Sprinkle with salt and pepper to taste. This simple seasoning process enhances the natural flavors and makes a world of difference in your spaghetti squash with mushrooms and kale dish.
Step 4: Roast the Squash
Place the squash cut side down on a baking sheet. Roast it in the oven for about 30-40 minutes. To check for doneness, poke it with a fork. If it easily pierces the flesh, it’s ready! The goal is tender strands that will mimic pasta beautifully.
Step 5: Caramelize the Onions
While the squash is roasting, let’s caramelize those onions! In a large skillet, heat butter and olive oil over medium heat. Add the sliced onions and cook them slowly for about 15-20 minutes. Stir occasionally to prevent burning. You want them golden brown and sweet—this is where the magic happens!
Step 6: Add Mushrooms and Kale
Once your onions are beautifully caramelized, it’s time to add the mushrooms and kale. Toss them into the skillet and cook for another 5-7 minutes. The mushrooms will soften, and the kale will wilt, creating a colorful and nutritious mix for your kale spaghetti squash recipe.
Step 7: Combine and Serve
Finally, when the squash is done roasting, use a fork to scrape the flesh into spaghetti-like strands. Combine the squash with the caramelized onion mixture in the skillet. Toss everything together until well mixed. Serve warm, and if you like, top with a sprinkle of parmesan cheese for that extra touch!
Tips for Success
- Use a sharp knife to cut the spaghetti squash safely and easily.
- Don’t rush the caramelization process; low and slow is key for sweet, rich onions.
- Feel free to experiment with other veggies like bell peppers or zucchini.
- For added flavor, try using garlic when sautéing the onions.
- Store leftovers in an airtight container for up to three days.
Equipment Needed
- Sharp Knife: Essential for cutting the spaghetti squash. A serrated knife works well too.
- Baking Sheet: Use a rimmed baking sheet to catch any drips while roasting.
- Large Skillet: A non-stick skillet is great for caramelizing onions without sticking.
- Fork: Needed for scraping the squash into strands.
Variations To Try
- Spicy Kick: Add a pinch of red pepper flakes when sautéing the onions for a bit of heat.
- Herb Infusion: Experiment with different herbs like thyme or basil for a fresh twist on flavor.
- Protein Boost: Toss in cooked chicken, shrimp, or chickpeas for a heartier meal.
- Cheesy Delight: Mix in some ricotta or goat cheese for a creamy texture that pairs beautifully with the squash.
- Nutty Crunch: Top with toasted pine nuts or walnuts for added texture and flavor.
Serving Suggestions
- Pair with a crisp green salad for a refreshing contrast.
- Serve alongside grilled chicken or fish for a complete meal.
- Enjoy with a glass of white wine, like Sauvignon Blanc, to complement the flavors.
- Garnish with fresh herbs for a pop of color and flavor.
- For a cozy touch, serve in the squash halves for a beautiful presentation.
FAQs about Caramelized Onion Spaghetti Squash
Can I make this Caramelized Onion Spaghetti Squash ahead of time?
Absolutely! This dish is perfect for meal prep. You can prepare the caramelized onions and roast the squash in advance. Just store them separately in the fridge and combine them when you’re ready to serve. It reheats beautifully!
What can I substitute for kale in this recipe?
If kale isn’t your favorite, feel free to swap it out for spinach or Swiss chard. Both options will add a lovely color and nutrition to your spaghetti squash with mushrooms and kale dish.
Is this recipe gluten-free?
Yes, indeed! This gluten-free squash casserole is made entirely with gluten-free ingredients, making it a safe choice for those with gluten sensitivities.
Can I add protein to this dish?
Definitely! You can toss in cooked chicken, shrimp, or even chickpeas for a protein boost. This makes it a heartier meal while still keeping it a low-carb vegetarian dinner squash.
How do I know when the spaghetti squash is done roasting?
The best way to check is by poking it with a fork. If it easily pierces the flesh, it’s ready! You want those strands to be tender and ready to soak up all the delicious flavors from the caramelized onions.
Conclusion
Cooking Caramelized Onion Spaghetti Squash is more than just making dinner—it’s about creating a comforting dish that brings everyone to the table. The golden onions and tender squash make every bite a balance of sweet and savory that feels hearty yet nourishing.
For more spaghetti squash inspiration, try my bold Buffalo Chicken Stuffed Spaghetti Squash or family-style Mexican Spaghetti Squash Casserole. Both are wholesome, flavorful, and perfect for adding variety to your dinner rotation.
So roll up your sleeves, caramelize those onions, and enjoy a dish that’s as comforting as it is nutritious. Did you enjoy this recipe? Save it on Pinterest so you can find it easily, and subscribe to my newsletter for weekly ideas your family will love.