Ingredient

• 2 medium (about 2 pounds each) spaghetti squash, cut crosswise into 2-inch thick rounds
• 1/4 cup olive oil, divided
• 1/2 teaspoon black pepper
• 1 1/2 teaspoons fine salt, divided
• 6 cloves garlic, chopped
• 1 large yellow onion, chopped (about 2 cups)
• 1 pound 90/10 lean ground beef
• 2 tablespoons tomato paste
• 1 (28-ounce) can whole peeled plum tomatoes
• 1 teaspoon dried oregano
• 1 teaspoon fennel seeds, optional
• 1/2 teaspoon crushed red pepper
• 1 cup (4 ounces) shredded low-moisture part-skim mozzarella
• 1/4 cup finely grated parmesan
• Chopped fresh basil, for garnish

Direction

1. Gather the ingredients. Preheat the oven to 425 F. Line a large baking sheet with parchment paper.
2. Scoop the seeds out of the squash rings and arrange the rings in a single layer on the prepared baking sheet. Brush both sides of the rings evenly with 2 tablespoons olive oil and sprinkle evenly with 1/2 teaspoon black pepper and 1 teaspoon fine salt. Bake until tender, about 40 minutes.
3. While the squash roasts, heat the remaining 2 tablespoons olive oil in a large Dutch oven over medium. Add 6 garlic cloves, chopped and 1 large yellow onion, chopped. Cook, stirring often, until tender and aromatic, about 8 minutes.
4. Increase the heat to medium-high and stir in 1 pound 90/10 lean ground beef. Cook, stirring often and using the back of a spoon to break up the meat, until no longer pink, about 6 minutes.
5. Stir in 2 tablespoons tomato paste. Cook, stirring constantly, until the paste is well-browned and forms a dark layer on the bottom of the pan, about 1 minute.
6. Stir in 1 (28-ounce) can whole peeled plum tomatoes, 1 teaspoon dried oregano, 1 teaspoon fennel seeds (if using), 1/2 teaspoon crushed red pepper, and remaining 1/2 teaspoon fine salt. Use the back of the spoon to break the tomatoes into smaller pieces. Bring the sauce to a simmer over medium. Cook, stirring occasionally, until the flavors meld and the liquid reduces and thickens, 20 to 25 minutes.
7. Remove the squash from the oven and let sit until cool enough to handle, about 5 minutes. Reduce the oven temperature to 400 F. Using a fork, pull the squash into noodle-like strands and discard the skins. You should have about 5 cups of squash. 
8. Add the squash to the sauce and stir to coat.
9. Transfer the squash mixture to an ungreased 13 x 9-inch baking dish. Sprinkle evenly with 1 cup (4 ounces) shredded low-moisture part-skim mozzarella and 1/4 cup finely grated parmesan. 
10. Bake until the cheese is golden brown and melted, 20 to 25 minutes. Remove the casserole from the oven and let sit for 5 minutes. Garnish with chopped fresh basil before serving.