Keto Chicken Alfredo Spaghetti Squash Boats

Why You’ll Love This Recipe

• All the creamy, garlicky comfort of chicken Alfredo with a keto-friendly spaghetti squash base.
• Broiled mozzarella on top creates a bubbly, golden, irresistible finish.
• Weeknight-friendly: roast the squash while you sear the chicken and whisk the quick Alfredo.
• One-pan finish and built-in portioning—each squash half is its own “boat.”

Grocery List

• Produce: 2 spaghetti squash, 4 garlic cloves, fresh parsley
• Dairy: Unsalted butter, heavy cream, cream cheese, Parmesan, low-moisture mozzarella
• Pantry: Extra-virgin olive oil, kosher salt, black pepper, Italian seasoning, garlic powder, paprika, ground nutmeg, red pepper flakes (optional)

Full Ingredients

For the Spaghetti Squash Boats

• 2 medium spaghetti squash (about 2 to 2.5 lb each), halved lengthwise and seeded
• 2 tbsp extra-virgin olive oil
• 1 tsp kosher salt
• 1/2 tsp freshly ground black pepper

For the Chicken

• 1.25 lb boneless, skinless chicken breasts (2 large), pounded to 1/2-inch even thickness
• 1 tbsp extra-virgin olive oil
• 3/4 tsp kosher salt
• 1/2 tsp freshly ground black pepper
• 1 tsp Italian seasoning
• 1/2 tsp garlic powder
• 1/4 tsp sweet paprika

For the Alfredo Sauce

• 2 tbsp unsalted butter
• 4 garlic cloves, finely minced
• 1 cup heavy cream
• 2 oz cream cheese, cut into small cubes and softened
• 1 cup very finely grated Parmesan cheese (about 3 oz), plus more for serving
• 1/8 tsp ground nutmeg
• 1/4 tsp red pepper flakes (optional)
• 1/2 tsp kosher salt, or to taste
• 1/4 tsp freshly ground black pepper

For Topping & Garnish

• 1.5 cups shredded low-moisture whole-milk mozzarella (about 6 oz)
• 2 tbsp chopped fresh parsley
• Extra grated Parmesan, to taste

Step-by-Step Instructions

Step 1: Roast the spaghetti squash

Preheat the oven to 400°F with a rack in the center. Line a large rimmed sheet pan with parchment. Brush the cut sides of the squash with 2 tbsp olive oil and season with 1 tsp kosher salt and 1/2 tsp pepper. Place cut-side down on the pan. Roast for 40 minutes, until the shells give slightly when pressed and a fork easily pulls spaghetti-like strands. If your squash are larger than 2.5 lb, roast an additional 5 to 10 minutes.

Step 2: Season and sear the chicken

While the squash roasts, pat the chicken dry and pound to an even 1/2-inch thickness. In a small bowl, combine 3/4 tsp salt, 1/2 tsp pepper, Italian seasoning, garlic powder, and paprika. Rub chicken with 1 tbsp olive oil and the seasoning blend.

Heat a large skillet over medium-high. Sear chicken 4 to 5 minutes on the first side and 3 to 4 minutes on the second, until deeply golden and the internal temperature reaches 160°F. Transfer to a cutting board, tent loosely with foil, and rest 5 minutes (carryover will reach 165°F). Slice across the grain into bite-size strips.

Step 3: Make the velvety Alfredo sauce

Reduce the skillet heat to medium. Add butter; when melted and foamy, add garlic and cook 30 to 45 seconds until fragrant but not browned. Stir in heavy cream and bring to a gentle simmer for 2 minutes. Whisk in the cream cheese until completely smooth.

Remove the pan from the heat and gradually whisk in the Parmesan until melted and silky. Season with nutmeg, red pepper flakes (if using), 1/2 tsp kosher salt (or to taste), and 1/4 tsp pepper. Keep warm over very low heat; avoid boiling to prevent separating.

Step 4: Shred the squash and toss with sauce

Remove the roasted squash from the oven and let cool just until safe to handle. Flip cut-side up. Using a fork, scrape to loosen long, spaghetti-like strands, leaving a 1/4-inch border so the shells stay sturdy for stuffing. Transfer the strands to a large bowl. Pour in about two-thirds of the Alfredo sauce and toss to coat. Taste and adjust salt and pepper as needed.

Step 5: Assemble the boats

Return the sauced squash strands to the four shells, dividing evenly. Nestle the sliced chicken over the top. Spoon the remaining Alfredo sauce over the chicken and squash. Sprinkle each boat evenly with shredded mozzarella.

Step 6: Broil until bubbly and golden

Move an oven rack to the upper third and set the broiler to high. Broil the boats 2 to 4 minutes, rotating the pan once, until the mozzarella is melted, bubbling, and spotty golden brown. Watch closely to prevent burning.

Step 7: Finish and serve

Let the boats rest 3 to 5 minutes to set. Shower with chopped parsley and extra Parmesan. Serve hot straight from the shells.

Pro Tips

• If cutting hard squash is tricky, microwave each whole squash for 2 to 3 minutes to slightly soften the rind before halving.
• For the creamiest sauce, remove the pan from heat before adding Parmesan and use very finely grated cheese so it melts smoothly.
• Do not boil the Alfredo; gentle heat keeps the sauce glossy and prevents separation.
• Pound chicken to even thickness for juicier, more evenly cooked slices.
• Broilers vary—keep the pan 6 inches from the element and watch constantly during the final minute.

Variations

• Cajun Chicken Alfredo: Swap Italian seasoning for 1 tsp Cajun seasoning and add a squeeze of lemon at the end.
• Florentine: Stir 3 cups baby spinach into the hot sauce to wilt, and add 1 cup sautéed mushrooms before assembling.
• Broccoli Alfredo: Toss 2 cups steamed small broccoli florets with the squash strands before returning to the shells.

Storage & Make-Ahead

Refrigerate leftovers in airtight containers for up to 4 days. Reheat, covered, at 350°F for 15 to 20 minutes, or microwave on 60% power for 2 to 3 minutes until hot. You can roast the squash and cook the chicken 1 to 2 days ahead; store separately, then make the sauce and assemble before broiling. Freezing is not recommended (cream sauces can separate and squash can become watery).

Nutrition (per serving)

Approximate: 760 calories; 58 g fat; 44 g protein; 13 g total carbs; 2 g fiber; 11 g net carbs. Nutrition will vary based on brands and exact weights.