Preheat your oven to 350°F (175°C).

In a large skillet over medium heat, brown the ground beef with the chopped onion and minced garlic until the beef is no longer pink. Drain excess fat.

Stir in the tomato sauce, diced tomatoes, Italian seasoning, salt, and black pepper. Bring to a simmer.

Add the uncooked elbow macaroni and beef broth to the skillet. Stir well to combine.

Cover the skillet and let it simmer for about 10 minutes, stirring occasionally, until the macaroni is tender and most of the liquid is absorbed.

Remove from heat and stir in half of the mozzarella cheese.

Transfer the mixture to a greased 9x13 inch baking dish. Top with the remaining mozzarella cheese and sprinkle with Parmesan cheese.

Bake in the preheated oven for 20-25 minutes, or until the cheese is bubbly and golden.

Remove from the oven and let it cool for 5 minutes before serving. Garnish with chopped parsley if desired.