Sausage Peppers Spaghetti Squash

The first time I made this spaghetti squash casserole, my husband actually thought it was regular pasta. He took three bites before looking at me with wide eyes and asking how I managed to make noodles taste so good while keeping them low-carb. Now it's become our go-to comfort food when we want something hearty without the heavy feeling afterwards.

I originally developed this recipe when my sister was visiting and watching her carb intake. She was skeptical about squash replacing pasta, but after dinner she literally asked me to write down the recipe before she left. Now she makes it for her family every Sunday.

Ingredients

• 1 large spaghetti squash: Look for one that feels heavy for its size with a hard, unblemished skin
• 1 red bell pepper and 1 yellow bell pepper: The combination adds sweetness and gorgeous color contrast
• 1 small yellow onion: Thinly sliced for even cooking and sweet flavor
• 2 cloves garlic: Minced fresh releases more flavor than garlic powder ever could
• 12 oz Italian sausage: Mild or hot depending on your spice preference, casings removed
• 1 1/2 cups marinara sauce: Choose a good quality brand or homemade with San Marzano tomatoes
• 1 cup shredded mozzarella: Freshly shredded melts better than pre-shredded
• 1/4 cup grated Parmesan: Adds that essential salty umami finish
• 2 tbsp olive oil: Extra virgin for roasting the squash and sautéing vegetables
• 1/2 tsp dried oregano: Earthy Mediterranean flavor that complements the sausage perfectly
• 1/2 tsp dried basil: Sweet herbaceous notes that bridge the vegetables and sauce
• 1/4 tsp crushed red pepper flakes: Optional but recommended if you love gentle heat
• Salt and black pepper: Essential for bringing out all the flavors
• Fresh basil: For garnish adds bright fresh color and aroma

Instructions

Roast the squash:

Preheat your oven to 400°F and line a baking sheet with parchment. Cut the spaghetti squash in half lengthwise, scoop out those seeds, brush the cut sides with olive oil, and season generously with salt and pepper. Place them cut-side down and roast for 35-40 minutes until tender.

Cook the sausage and vegetables:

While the squash roasts, heat olive oil in a large skillet over medium heat. Add the sausage, breaking it up with a spoon, and cook until browned. Toss in onions and bell peppers, sauté for 5 minutes, then stir in garlic and herbs for one final minute.

Combine everything:

Pour in the marinara sauce and simmer for 5 minutes. Scrape the roasted squash into strands with a fork. Reduce the oven to 375°F, then mix squash strands with the sausage mixture and half the cheeses in a large bowl.

Bake until bubbly:

Transfer everything to a greased 9x13 baking dish, top with remaining cheese, and bake uncovered for 15-20 minutes until golden and bubbling. Let it rest 5 minutes before serving.

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Last winter my neighbor smelled this baking and actually knocked on my door to ask what I was making. We ended up having an impromptu dinner party with their family and mine, all gathered around this bubbling casserole on a cold Tuesday night.

Make Ahead Magic

I love assembling this casserole in the morning, keeping it covered in the fridge, then just baking it when I get home from work. The flavors actually meld better when they have time to hang out together.

Cheese Choices

Sometimes I swap in provolone for half the mozzarella when I want a sharper bite. A little grated fontina mixed in creates the most incredible stretchy cheese pull you've ever seen.

Serving Suggestions

A crisp green salad with red wine vinegar dressing cuts through the richness perfectly. Garlic bread on the side is totally allowed even though this is already pasta-like.

• Let leftovers cool completely before refrigerating to prevent condensation
• Freeze individual portions for easy future weeknight meals
• Add red pepper flakes at the table so everyone controls their spice level

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This recipe proves that eating low-carb never means sacrificing comfort or flavor. Enjoy every cheesy, savory bite.

Recipe Questions & Answers

→ How do you prepare the spaghetti squash for this dish?

Cut the squash in half lengthwise, scoop out the seeds, brush with olive oil, season, and roast cut-side down until tender. Then scrape out strands with a fork.

→ What type of sausage works best?

Italian sausage, either mild or hot, is ideal. For variations, plant-based or turkey sausage can be used.

→ Can this dish be made ahead of time?

Yes, the components can be assembled in advance and baked just before serving for convenience.

→ What cheeses are used in the topping?

Mozzarella and Parmesan provide a rich, melted topping that bubbles and browns beautifully during baking.

→ Is this suitable for a gluten-free diet?

When using gluten-free marinara sauce and sausage, the dish is appropriate for gluten-free diets.

→ How can the spice level be adjusted?

Use spicy Italian sausage or add crushed red pepper flakes to increase heat, or omit for milder flavor.