Preheat your oven to 350°F (175°C).
In a large skillet, heat the olive oil over medium heat. Add the chopped onion and green bell pepper, sautéing until they are soft and the onion is translucent, about 5 minutes. Stir in the minced garlic and cook for an additional minute until fragrant.
Add the ground beef to the skillet. Break it up with your spatula and cook until browned and fully cooked, about 6-8 minutes. Drain any excess fat if necessary.
To the skillet, add the uncooked rice, diced tomatoes, beef broth, oregano, paprika, salt, and pepper. Stir everything together until well combined.
Pour the mixture into your greased 9x13 inch baking dish, spreading it out evenly.
Cover the dish with aluminum foil and bake in the preheated oven for 40 minutes.
After 40 minutes, remove the foil and sprinkle the shredded cheddar cheese on top. Return to the oven and bake for an additional 10-15 minutes, or until the cheese is melted and bubbly.
Once out of the oven, let the casserole sit for about 5-10 minutes before serving.