With tender roasted squash and a rich, homemade Alfredo, this Spaghetti Squash Alfredo is a simple, low-carb, keto-friendly dish that works well as a side or a satisfying vegetarian main.
We love classic pasta, and nothing quite replaces a bowl of fresh, creamy spaghetti. Still, roasted spaghetti squash is a delicious, lighter alternative when you want to cut calories or carbs. When roasted properly and paired with a flavorful sauce, it becomes a comforting dish that’s full of texture and taste.
I often roast spaghetti squash as a side, but it shines as an entrée when combined with one of my favorite sauces—homemade Alfredo. Perfectly roasted squash plus a silky, cheesy sauce makes a crowd-pleasing, keto-friendly meal that’s easy to prepare and sure to impress.
What’s in this Low Carb Spaghetti Squash Alfredo recipe?
This recipe uses a short list of wholesome ingredients and a few seasonings. Exact amounts are shown in the recipe card below.
- Spaghetti squash – about a 3-pound squash works well for the quantities below.
- Heavy whipping cream – creates a lush base for the Alfredo sauce.
- Unsalted butter – adds richness; if you use salted butter, taste the sauce before adding extra salt.
- Garlic – a combination of fresh garlic and garlic powder gives depth; reduce either for a milder garlic flavor.
- Seasonings – Italian seasoning, salt, black pepper, red pepper flakes, and a hint of nutmeg round out the sauce.
- Parmesan cheese – freshly grated Parmesan or Parmigiano-Reggiano offers the best flavor and texture.
- Chopped parsley & lemon wedges – optional garnishes to brighten the finished dish.
Tips & Variations
Small adjustments make a big difference. Follow these tips for tender squash and a smooth, velvety sauce, and consider these variations to suit your taste.
- Don’t overcook the squash. Roast until fork-tender but still slightly al dente so the strands hold their texture instead of becoming mushy.
- Avoid boiling the sauce. Keep the cream mixture at a gentle simmer; boiling can cause curdling.
- Whisk constantly. Continuous whisking prevents the sauce from sticking or scorching and helps it thicken evenly.
- Add protein if desired. Stir in cooked chicken, shrimp, or crisp bacon for a heartier meal.
- Swap sauces. If Alfredo isn’t your preference, spaghetti squash pairs beautifully with tomato-based sauces like marinara or traditional spaghetti sauce.
Serving Suggestions
Serve Spaghetti Squash Alfredo as a low-carb entrée, garnished with cracked black pepper and chopped parsley. A squeeze of lemon just before serving brightens the flavors and balances the richness.
For a heartier plate, add grilled or roasted chicken, sautéed shrimp, or crispy bacon. A fresh side salad complements the creamy dish well. If you’re not limiting carbs, garlic bread also pairs nicely.
How to Store & Reheat Leftovers
- Fridge life: Cooked spaghetti squash and Alfredo will keep for up to 4 days when stored in airtight containers.
- Storage: Store squash and sauce together or separately; either method works fine for reheating.
- Reheating: Reheat gently in a saucepan over low heat or in short intervals in the microwave, stirring occasionally to maintain creaminess.
If you make this recipe, please leave a review below. Enjoy preparing and sharing this comforting, low-carb dish!
Spaghetti Squash Alfredo
Ingredients
- 3 pound spaghetti squash, cleaned and dried
- 1 tablespoon olive oil
- 1 & 1/2 cups heavy whipping cream
- 1/2 cup butter, cut into cubes
- 2 cloves garlic, minced
- 1/2 teaspoon garlic powder
- 1/2 teaspoon dried Italian seasoning
- 1/4 teaspoon coarse salt
- 1/4 teaspoon cracked black pepper
- 1/8 teaspoon crushed red pepper flakes
- 2 cups freshly grated Parmesan cheese
- 1 tablespoon chopped parsley, for garnish
Instructions
Roast the squash
- Preheat the oven to 400°F.
- Cut the squash in half lengthwise and scoop out the seeds. Drizzle the cut sides with olive oil and place them face down on a baking sheet. Roast for about 1 hour, or until the squash is fork tender.
- Use a fork to scrape the flesh into long, spaghetti-like strands. Transfer the strands to a large bowl and keep warm.
Make the Alfredo Sauce
- In a large nonstick saucepan over medium-low heat, combine the heavy cream and cubed butter, whisking until the butter melts. Add the minced garlic, garlic powder, Italian seasoning, coarse salt, cracked black pepper, and crushed red pepper flakes; whisk until smooth.
- Increase the heat slightly and bring the mixture to a gentle simmer—do not boil. Cook for 3–5 minutes, whisking constantly, until the sauce thickens and reduces slightly. Remove from heat and stir in the grated Parmesan until melted and smooth. If the sauce needs more time to thicken, let it stand for 2–3 minutes before combining with the squash.
- Toss the cooked squash strands with the Alfredo sauce until evenly coated.
Assemble the Spaghetti Squash Alfredo
- Spoon the sauced squash back into the empty squash halves or divide it onto plates.
- Top with extra shaved Parmesan and chopped parsley. Serve warm and enjoy.
Notes
Nutrition
Nutritional information is an estimate and can vary depending on exact ingredients and portions used.
More Alfredo Recipes:
- Chicken Alfredo Pizza
- Chicken Alfredo Lasagna Rolls
- Homemade Alfredo Sauce
- The best Chicken Alfredo
- Chicken Alfredo Tortellini Soup
- Chicken Alfredo Bake