Preheat your oven to 350°F (175°C).
In a large skillet, heat the olive oil over medium heat. Add the diced onion and cook until translucent, about 5 minutes.
Add the minced garlic and ground beef to the skillet. Cook until the beef is browned and cooked through, breaking it apart with a spoon, about 7-10 minutes. Drain any excess fat.
Stir in the diced tomatoes, cannellini beans, beef broth, oregano, basil, salt, and black pepper. Bring the mixture to a simmer and let it cook for 5 minutes.
In a large mixing bowl, combine the cooked pasta with the beef mixture. Stir until well combined.
Transfer the mixture to a greased 9x13 inch baking dish. Top with shredded mozzarella cheese.
Bake in the preheated oven for 25-30 minutes, or until the cheese is bubbly and golden brown.
Remove from the oven and let it cool for a few minutes. Garnish with chopped parsley before serving.