In a large bowl, combine the minced turkey, chopped onion, minced garlic, breadcrumbs, egg, grated cheddar cheese (if using), olive oil, dried oregano, dried basil, salt, and black pepper. Mix everything together with your hands until just combined – be careful not to overmix.

Using your hands, shape the mixture into meatballs, roughly 1 1/2 inches (3.8 cm) in diameter. You should end up with around 30-40 meatballs.

Preheat a large non-stick skillet or grill pan over medium-high heat. When the pan is hot, add a few meatballs and cook until browned on all sides and cooked through, about 5-7 minutes per side. Repeat with the remaining meatballs.

While the meatballs are cooking, spiralize the zucchinis into long, thin noodles. Set aside.

In a separate saucepan, heat the marinara sauce over medium heat. Add the cooked meatballs to the saucepan and let them simmer in the sauce for a few minutes to coat them evenly.

Using a pair of tongs or a long-handled fork, add the zucchini noodles to the saucepan with the meatballs and sauce. Toss everything together to combine.

Serve the High-Protein Turkey Meatball Meal Prep with Zoodles immediately, garnished with grated mozzarella cheese (if using) and chopped fresh parsley. Alternatively, transfer the meal prep to airtight containers and refrigerate or freeze for later use.