Preheat your oven to 375°F (190°C) and grease a 9x13-inch baking dish.

In a large skillet, brown the ground beef over medium heat for 5-7 minutes. Drain excess fat.

Add diced onion and minced garlic to the skillet, sauté for 2-3 minutes until onion is translucent.

Stir in tomato sauce, diced tomatoes, Italian seasoning, salt, and black pepper. Allow to simmer for 5 minutes.

Cook elbow macaroni according to package instructions until al dente, about 7-9 minutes. Drain and set aside.

In a large mixing bowl, combine cooked macaroni, beef mixture, cheddar cheese, mozzarella cheese, and sour cream. Stir until evenly mixed.

Pour the mixture into the greased baking dish and sprinkle grated Parmesan cheese on top.

Bake for 25-30 minutes, until bubbly and cheese is melted to golden perfection.

Let it cool for about 5 minutes before serving.