Preheat your oven to 375°F (190°C).
Heat a large oven-safe skillet (such as a cast-iron skillet) over medium heat on the stovetop. Add the ground beef to the skillet, breaking it up with a spoon or spatula. Cook until the beef is browned and no longer pink, about 5-7 minutes. If necessary, drain excess grease from the skillet to reduce fat content.
Add the diced onion and minced garlic to the skillet with the browned beef. Cook, stirring occasionally, until the onion is translucent and the garlic is fragrant, about 3-4 minutes. Stir in the diced bell peppers and cook for an additional 3-4 minutes until they begin to soften.
Stir in the uncooked rice. Pour in 2 cups of beef broth or water.
Add the drained diced tomatoes, tomato sauce, salt, black pepper, Italian seasoning, and paprika. Combine all ingredients thoroughly to ensure the rice is submerged in the liquid.
Increase the heat to medium-high and bring the mixture to a gentle boil. Once boiling, reduce the heat to low, cover the skillet with a lid, and let it simmer for about 15-20 minutes. Check at 15 minutes. If the mixture is too dry before the rice is cooked, add an additional ½ cup of beef broth or water. Once cooked, remove the skillet from heat and fluff the rice mixture with a fork.
Sprinkle the shredded cheese over the top of the beef and rice mixture. Place the skillet in the preheated oven. Bake for 15-20 minutes, or until the cheese is melted and bubbly.
Carefully remove the skillet from the oven using oven mitts (the handle will be hot). Let the casserole cool for a few minutes. Sprinkle with freshly chopped parsley or basil if desired. Serve warm.