1. Preheat oven to 400°F (200°C). Cut spaghetti squash in half lengthwise and scoop out the seeds.

2. Brush the inside with olive oil and sprinkle with salt and pepper. Place cut-side down on a baking sheet and roast for 35–40 minutes.

3. While the squash roasts, heat remaining olive oil in a skillet over medium heat. Add diced onion and sauté until translucent.

4. Stir in garlic and cook for 1 minute. Add ground beef and cook until browned. Drain excess fat.

5. Stir in crushed tomatoes, Italian seasoning, salt, and pepper. Simmer for 10–15 minutes.

6. Once squash is cool enough to handle, use a fork to shred the flesh into spaghetti-like strands.

7. Place squash strands into the empty shells or a baking dish. Top evenly with meat sauce.

8. Sprinkle mozzarella and Parmesan cheese over the top.

9. Return to oven at 375°F for 10–15 minutes, or until cheese is bubbly. Broil for 2 minutes for a golden top.

10. Garnish with fresh basil or parsley and serve hot.