For marinara: Heat 1 tablespoon oil in a large saucepan. Add onions, carrots, and garlic. Sauté over medium heat until vegetables are just crisp-tender. Add zucchini, bell pepper and mushrooms; Sauté until vegetables are tender. Stir in tomatoes and seasonings. Simmer for 30 minutes. For a thinner more traditional sauce, puree marinara in a large food processor or blender. Return pureed marinara to large saucepan. Or use an immersion blender to partially puree the sauce. This will produce a chunkier sauce.
For turkey meatballs: Step 1) while marinara is simmering, combine ground turkey, egg, spinach, onion, basil, garlic powder, salt and black pepper in a large mixing bowl (clean hands work best for this).
Step 2) Portion into 16 meatballs (1-1/2 inch).
Step 3) Heat 1 tablespoon oil in a large nonstick skillet over medium-high heat. Add meatballs to skillet and brown all sides until cooked through, about 10 to 12 minutes. Remove meatballs from skillet and add to marinara sauce.
Step 4) Continue to cook marinara and meatballs for 10 minutes.
For spaghetti squash: Step 1) Pierce squash thoroughly with a sharp knife; about 1-inch in depth. Place squash on a plate or shallow microwave-safe casserole. Microwave squash on HIGH for 8 to 10 minutes. Turn over and continue to microwave on HIGH for an additional 8 to 10 minutes or until squash is soft when pressed. Remove from microwave; let sit 5 minutes to cool.
Step 2) Slice squash in half. Using a fork, lighlty scrape to remove seeds. Now, scrape the squash flesh from the skin into a large serving bowl. Top with marinara and turkey meatballs.
Recipe Tip- Spaghetti squash can be baked for 1 hour in a 350℉ oven; pierce squash prior to baking.