Preheat your oven to 350°F (175°C).
In a large skillet, brown the ground beef over medium heat until fully cooked, breaking it apart with a spatula, approximately 5-7 minutes.
Add the chopped onion to the skillet and sauté for another 3-4 minutes until the onion is translucent.
Stir in the cream of mushroom soup, beef broth, rice, diced tomatoes, garlic powder, salt, black pepper, and Italian seasoning. Mix everything well.
Allow the mixture to boil, then reduce the heat to low and cover. Cook for about 15 minutes, stirring occasionally, until the rice has absorbed most of the liquid.
Remove the skillet from heat and stir in half of the shredded cheddar cheese until melted.
Pour the mixture into a 9x13 inch baking dish, spreading it out evenly. Top with the remaining shredded cheese.
Bake in the preheated oven for 15 minutes or until the cheese is bubbly and slightly golden.
Remove from the oven and let it sit for 5 minutes before serving.