Preheat your oven to 350°F (175°C). This will ensure an even cooking temperature for the casserole.
In a large skillet, heat the olive oil over medium heat. Once hot, add the chopped onion and diced green bell pepper. Sauté for approximately 3-4 minutes until the vegetables are softened and the onion becomes translucent.
Add the minced garlic to the skillet and continue to sauté for about 1 minute until fragrant. Then, introduce the ground beef, breaking it up with a spatula. Cook until the beef is browned and no longer pink, which should take about 5-7 minutes. Season the mixture with salt, black pepper, Worcestershire sauce, smoked paprika, and dried oregano, stirring well to incorporate the flavors.
In a large mixing bowl, combine the uncooked long-grain rice, diced tomatoes (including their juice), cream of mushroom soup, and beef broth. Mix thoroughly to ensure a uniform consistency. Then, gently fold in the cooked beef and vegetable mixture until everything is well integrated.
Transfer the entire mixture into a greased 9x13-inch baking dish, spreading it out evenly.
Cover the dish tightly with aluminum foil to prevent moisture loss and bake in the preheated oven for 40 minutes.
After 40 minutes, carefully remove the foil, and sprinkle the shredded cheddar cheese evenly over the top of the casserole. Return it to the oven and bake uncovered for an additional 10-15 minutes, or until the cheese is melted, bubbly, and lightly golden.
Once baked, remove the casserole from the oven and allow it to cool for a few minutes to set. This will make serving easier.
To serve, garnish with freshly chopped parsley for a vibrant pop of color and added freshness.