Begin by preheating your oven to 375°F (190°C) so that it is ready for baking.
In a large skillet over medium heat, add the ground beef. Use a wooden spoon to break it apart while cooking, and continue until the beef is browned. Carefully drain any excess fat to keep the dish from becoming greasy.
Once the beef is browned, introduce the finely chopped onion and minced garlic into the skillet. Sauté these ingredients together for about 3-4 minutes, or until the onion turns translucent and fragrant.
Next, stir in the can of diced tomatoes (including the juice), uncooked elbow macaroni, beef broth, Italian seasoning, and season everything with salt and pepper to taste.
Bring this delicious mixture to a gentle boil, then reduce the heat to low and cover the skillet. Allow it to simmer for 10-12 minutes, checking occasionally, until the macaroni has softened.
Once the macaroni is tender, remove the skillet from the heat and fold in half of the shredded cheddar cheese and half of the mozzarella cheese. Stir well until thoroughly combined.
Lightly grease a 9x13 inch baking dish, then pour the beef and macaroni mixture into it, spreading it out evenly.
Sprinkle the remaining cheddar and mozzarella cheese generously over the top for that perfect cheesy finish.
Place the dish in the preheated oven and bake for 20-25 minutes, or until the cheese is deliciously bubbly and golden brown.
After baking, take the casserole out of the oven and let it cool for 5 minutes before slicing and serving. Finish the dish with a sprinkle of freshly chopped parsley for a pop of color and flavor.
Notes
Serve with a fresh green salad for a complete meal.