Spaghetti Squash with Alfredo is a low-carb, healthy alternative to classic pasta, bringing all the cheesy, garlicky goodness you crave without the extra carbs. Topped with juicy steak for a high-protein finish, this dish is just as satisfying as the original.

For more mouthwatering alfredo recipes, check out my Cheesy Chicken Alfredo Lasagna, Blackened Chicken Alfredo, and Bread Boat Chicken Alfredo next!

overhead view of sliced ribeye over a cheesy alfredo stuffed spaghetti squash

Spaghetti Squash Alfredo

I love pasta, but sometimes I want something lighter without sacrificing flavor. That’s where these squash boats come in—they give me all the comforting richness of Alfredo while cutting back on carbs. The roasted squash strands into perfect spaghetti-like "noodles", soaking up the garlicky, cheesy sauce.

Plus, the presentation is just as impressive as the taste, especially with tender steak on top. It’s a meal that feels indulgent but keeps things balanced.

Ingredients

Spaghetti Squash

Spaghetti squash: Once roasted, the inside shreds into tender strands that hold up well to the sauce.
Olive oil: Helps the squash caramelize while roasting, adding richness.
Salt + black pepper: Enhances the natural sweetness and balances flavors.

Alfredo Sauce

Olive oil + unsalted butter: A mix of fats that creates a flavorful base without burning.
Garlic, minced + onion, diced: Adds depth and a savory aroma that builds the foundation of the sauce.
Flour: Slightly thickens the sauce for a smooth, creamy consistency. Can be swapped for cornstarch or omitted if preferred.
Cream cheese: Gives the sauce a velvety texture with a mild tang that complements the parmesan.
Heavy cream or milk: Creates a rich base, with heavy cream making it thicker and milk keeping it a bit lighter.
Parmesan cheese, grated: Adds saltiness and depth. Freshly grated works best for melting evenly.
Seasoned salt: Provides extra flavor beyond just standard salt.
Garlic powder + Italian seasoning + black pepper: A balanced mix of seasoning that ties everything together.

Steak

Ribeye steak: Tender and flavorful with just the right amount of marbling. Other cuts like sirloin can work too.
Steak seasoning: A blend of salt, pepper, and spices that enhances the crust when seared.
Worcestershire sauce: Adds umami and a hint of sweetness for a deeper flavor.
Unsalted butter: Helps create a rich, golden crust while cooking.

Toppings

Mozzarella cheese: Melts smoothly and creates a gooey finish.
Grated parmesan cheese: A final layer of saltiness that complements the Alfredo.
Fresh basil, chopped (optional): Adds color and a fresh, slightly sweet contrast to the creamy sauce.

Two sliced spaghetti squashes, baked and filled with alfredo, steak and more cheese. Basil is on the side for garnish.

How to Make Spaghetti Squash with Alfredo

See recipe card for ingredient quantities and full instructions.

Roasting the Spaghetti Squash

I start by preheating my oven to 400°F. Using a sharp knife, I cut the spaghetti squash in half lengthwise, from stem to bottom, and scoop out the seeds. A drizzle of olive oil, salt, and pepper adds flavor before placing the squash cut-side down on a baking sheet.

To help it steam, I poke the skin side with a fork about 10 times. Then, I bake it for 30 minutes until it's fork-tender. Once it’s done, I take it out and let it cool.

Making the Alfredo Sauce

While the squash roasts, I start on the sauce. In a skillet over medium heat, I melt butter with a little olive oil. Once hot, I sauté the garlic and onions for a minute or two until fragrant.

Next, I sprinkle in the flour and stir until it absorbs the oils. I add the cream cheese and let it melt slightly before pouring in the heavy cream, stirring everything together. The sauce may look a little chunky at first, but it smooths out as it simmers.

I mix in the parmesan, seasoned salt, garlic powder, Italian seasoning, and black pepper. Letting it simmer on low for five minutes thickens it up. If it gets too thick, I add a splash of cream or broth until it reaches the right consistency.

Cooking the Steak

I season my ribeye with steak seasoning and Worcestershire sauce, letting it marinate for at least an hour if I have time. When ready, I heat a cast iron skillet over medium-high heat and melt some butter.

Once the butter is hot, I place the steak in the skillet and press it down to get a nice sear. I cook it for about five minutes per side for a medium finish, then remove it and let it rest for seven minutes before slicing into thin strips.

Assembling the Spaghetti Squash with Alfredo Sauce

Once the squash is cool enough to handle, I use a fork to shred the inside into spaghetti-like noodles while keeping the shell intact. In a large bowl, I toss the shredded squash with the Alfredo sauce until fully coated.

I scoop the mixture back into the squash shells, then top with mozzarella and sliced steak. A quick broil for about five minutes melts the cheese into a bubbly, golden topping—watching closely so it doesn’t burn.

Shredded mozzarella cheese over two sliced of baked spaghetti squash

Final Touches

For extra flavor, I finish with fresh basil and a sprinkle of parmesan. If I want a heartier meal, I serve it with a side salad or roasted veggies. This dish is rich, cheesy, and satisfying while keeping things low-carb and full of flavor.

Pro Tips

Roast the squash cut-side down. This helps trap steam inside, making the strands more tender and easy to shred. Poking holes in the skin also prevents it from bursting.
Let the steak rest before slicing. Cutting too soon will cause all the juices to run out, making the meat drier. Resting for at least 7 minutes keeps it juicy and flavorful.
Use freshly grated parmesan for the Alfredo sauce. Pre-shredded cheese often contains anti-caking agents that prevent it from melting smoothly. Freshly grated melts better and gives the sauce a richer flavor.
Watch the squash while broiling. The cheese can go from golden and bubbly to burned very quickly under high heat. Keep an eye on it and pull it out as soon as it’s melted to your liking.
Adjust the sauce consistency as needed. If it’s too thick, add a splash of cream, milk, or broth to loosen it. If too thin, let it simmer longer until it thickens up.

Storage

Store leftovers in an airtight container, and it will last up to 5 days in the fridge. When you are ready to reheat, just add it to a warm skillet and stir frequently. Reheat spaghetti squash alfredo gently in a warm skillet, stirring frequently to prevent separation.

Recipe Variations

Meat Options: Swap the steak for chicken Alfredo with spaghetti squash by using precooked chicken, like shredded rotisserie chicken or leftover chicken breast. Shrimp is another great option, adding a slightly sweet, tender bite that pairs well with the creamy sauce.
Keto-Friendly Adjustments: To keep this dish low-carb, replace the flour with almond flour or xanthan gum as a thickener. Stick to heavy cream instead of milk, and check that your Worcestershire sauce and steak seasoning are free from added sugars.
Boost the Veggies: Add broccoli, spinach, or mushrooms for extra flavor and nutrients. Stir them into the Alfredo sauce while it simmers, or roast them alongside the squash for added texture.

Two baked squashes filled with alfredo and topped with steak

FAQ

What is spaghetti squash?

Spaghetti squash is a winter vegetable that’s popular in low-carb and keto-friendly meals. It's known for its yellowish flesh that closely resembles spaghetti. When the flesh of the squash is cooked, it shreds easily with a fork. It has a mild flavor, which makes it the perfect pasta alternative.

Is spaghetti squash really healthy for you?

Yes! Spaghetti squash is a low-carb, nutrient-dense alternative to pasta. It's packed with fiber, vitamins C and B6, and antioxidants while being naturally low in calories. Plus, it provides a good amount of hydration since it's mostly water, so it's a great lighter option.

Can I make this ahead of time?

You can definitely make spaghetti squash with Alfredo ahead of time! I suggest preparing the squash and steak prior if you need to save time. For the best results, alfredo should be made fresh. It only takes minutes to prepare, and it makes all the difference.

Is spaghetti squash a good replacement for pasta?

It depends on what you’re looking for. Spaghetti squash has a lighter, slightly sweet flavor and a more tender texture than traditional pasta, so it won’t be an exact match. But if you want a low-carb, nutrient-rich alternative that still pairs well with sauces, it’s a great option!

More Low-Carb Recipes

Looking for other recipes like this? Try these:

After you try this Spaghetti Squash Alfredo recipe, I'd love to hear your thoughts. Comment below and follow me on Facebook, Instagram, Pinterest, and YouTube for more delicious recipes!

📖 Recipe

Close up view of sliced steak over spaghetti squash alfredo

Low Carb Spaghetti Squash with Alfredo and Steak

Spaghetti Squash with Alfredo is a low-carb, healthy alternative to classic pasta, bringing all the cheesy, garlicky goodness you crave without the extra carbs. Topped with juicy steak for a high-protein finish, this dish is just as satisfying as the original.

Print Recipe Save Rate Recipe

Prep Time: 10

Cook Time: 45

Total Time: 55

Course: dinner

Cuisine: American

Keyword: Chicken alfredo with spaghetti squash, Spaghetti squash alfredo, Spaghetti squash with alfredo, Spaghetti squash with alfredo sauce

Servings: Servings

Calories: 971kcal

Author: Tamara J.

Ingredients

1 medium Spaghetti squash
2 tablespoons Olive oil
1 teaspoon Salt
1 teaspoon Pepper

Alfredo Sauce

1 tablespoon Olive oil
1 tablespoon Butter unsalted
3 cloves Garlic minced
¼ cup Onion diced
1 tablespoon Flour
4 ounces Cream cheese
2 cups Heavy cream or milk
½ cup Parmesan cheese grated
½ tablespoon Seasoned salt
1 teaspoon Garlic powder
1 teaspoon Italian seasoning
1 teaspoon Black pepper

Steak

12 ounce Ribeye steak
1 tablespoon Steak seasoning
1 tablespoon Worcestershire sauce
2 tablespoons Butter unsalted

Topping

1 cup Mozzarella cheese
Grated parmesan
Basil chopped (optional)

Instructions

Preheat the oven to 400 degrees. Using a sharp knife, cut the spaghetti squash lengthwise, from stem to bottom.
Use a spoon to scoop out all of the seeds and membrane from the middle of each half of the squash.
Drizzle each half of the spaghetti squash with the olive oil, and salt and pepper. Place it cut side down on a baking sheet. Use a fork to pierce the skin side about 10 times to allow it to steam while it bakes.
Place the squash in the oven and bake for 30 minutes, or until the spaghetti squash is fork tender. Once it it is done, remove it and set it aside.

Alfredo Sauce

While the spaghetti squash is cooking, start on the alfredo sauce.
Warm up a skillet over medium heat. Add the olive oil and butter into the skillet. Once the butter is melted, add in the garlic and minced onions. Sauté for 1-2 minutes.
Sprinkle in the flour and stir it around until it absorbs the oils. Next place the cream cheese into the mixture and stir it around for about one minute so that it can begin to melt.
Gently pour in the heavy cream and stir it around until everything is incorporated. The sauce will be kind of chunky because of garlic and onions.
Add the parmesan cheese, seasoned salt, garlic powder, Italian seasoning, and black pepper.
Stir the alfredo sauce and allow it to simmer on low for 5 minutes. Add more heavy cream or broth if a thinner consistency is desired.

Steak

Season the steak with steak seasoning and Worcestershire sauce. Ideally the steak should marinate for at least one hour prior to cooking.
Heat up a cast iron skillet over medium high heat. Place the butter into the skillet and allow it to melt.
Once the butter is melted, place the steak directly into the skillet and press it down so that it can sear.
Sear the steak on each side for 5 minutes for a medium cook. Remove the steak from the skillet and allow it to rest for at least 7 minutes.
After the steak rests, slice it into thin strips.

Assemble the Spaghetti squash

Once the spaghetti squash is cool enough to handle. Use a fork to flesh out the strands of spaghetti. They should resemble noodles. Leave the shell of the squash in tact so that you can fill it.
Place the spaghetti squash in a large bowl. Pour the alfredo sauce over the squash and mix it in thoroughly.
Scoop the alfredo back into the shell of the spaghetti squash. Top with mozzarella cheese, and layer each half with the steak.
Place it back in the oven on the broil setting for 5 minutes, or until the cheese melts and bubbles. Keep a close eye on the it so that it does not burn.
Top with basil and parmesan cheese if desired.