Preheat your oven to 400°F (200°C).

1. Cut the spaghetti squash in half lengthwise. Scrape out the seeds and discard them. Drizzle the inside with olive oil and season with salt and pepper.
2. Place the squash halves cut-side down on a baking sheet lined with parchment paper. Roast for 35-40 minutes or until the flesh is tender and easily shredded with a fork. Once cooked, use a fork to scrape the flesh into strands, creating the ‘spaghetti’ texture. Set aside.
3. While the squash roasts, heat a skillet over medium heat. Add the ground beef and cook, breaking it apart with a spatula, until browned (5-7 minutes). Drain excess fat.
4. Add the chopped onion to the skillet and cook for 2-3 minutes until softened. Add the minced garlic and cook for another 30 seconds.
5. Stir in the tomato paste, oregano, basil, salt, pepper, and red pepper flakes (if using). Cook for 1-2 minutes.
6. Pour in the crushed tomatoes and beef broth. Stir well and bring to a simmer. Let the sauce cook for 10-15 minutes, until thickened and the flavors meld together.
7. Once the squash is cooked, divide the roasted spaghetti squash strands into bowls. Top with the beef sauce and stir to combine.
8. Serve as is, or garnish with grated Parmesan cheese and fresh basil for added flavor.