In a large skillet over medium heat, add the ground beef seasoned with Italian seasoning, salt, and pepper. Cook for about 6-8 minutes, stirring frequently, until browned.

In the same skillet, melt 2 tablespoons of butter over medium heat. Add the diced onions and sauté for 3-4 minutes until soft. Add minced garlic and stir for an additional minute.

Add sliced mushrooms and cook for about 5 minutes until softened. Stir in uncooked rice for 1-2 minutes to lightly toast it.

Pour in beef broth, mixing well. Return the browned beef to the skillet. Bring to a boil, then reduce heat, cover, and let simmer for 20 minutes.

Stir in cream of mushroom soup, milk, sour cream, and 1 cup of shredded cheddar cheese until well combined.

Transfer the mixture to a greased 9x13-inch baking dish. Sprinkle remaining cheese on top. Bake in preheated oven at 350°F (175°C) for 20 minutes.

Let rest for 5 minutes before serving. Garnish with fresh parsley or chives if desired.