Preheat the oven to 350°F and spray a casserole dish with non-stick cooking spray.

Heat the olive oil in a medium sized skillet over medium heat.

Add the diced onion, carrots, and garlic. Season with salt and pepper, to taste. Cook, stirring occassionally, until the vegetables are translucent, about 3-4 minutes.

Add the tomato sauce or puree and let the sauce simmer for 6-8 minutes.

Meanwhile, bring a large pot of salted water to a boil.

Cook pasta until al dente according to the package directions.

Drain the pasta and return it to the large pot. Add 1/3 of the tomato sauce to the pasta and stir to evenly coat the pasta.

Transfer the pasta to the prepared casserole dish.

In a medium sized mixing bowl, combine the ground beef, grated onion, breadcrumbs, parmesan cheese, egg, oregano, basil, and 1/2 of the fresh chopped parsley.

Season the mixture with salt and pepper and using your hands mix until just combined being careful not to overwork the mixture.

Roll the meat mixture into 14-16 meatballs and place on top of the pasta layer in the casserole dish.

Pour the remaining tomato sauce over the meatballs and then sprinkle the mozzarella cheese overtop.

Cover the casserole dish with aluminum foil and bake for 25 minutes.

Remove the foil and bake uncovered for another 15 minutes or until hot and bubbly and the cheese has melted and is golden-brown.

Serve garnished with the remaining fresh parsley. Enjoy!mi