In a large skillet over medium-high heat, brown the ground beef until fully cooked, breaking it apart with a wooden spoon or spatula as it cooks. Drain any excess fat if necessary.
Add the chopped onion and green bell pepper to the skillet with the cooked beef. Cook for a few minutes until the vegetables soften.
Stir in the long-grain white rice, diced tomatoes (with their juice), tomato sauce, beef broth, chili powder, garlic powder, paprika, cayenne pepper (if using), salt, and black pepper.
Heat the mixture until it reaches a boiling point, then lower the heat to low. Cover the skillet with a lid and simmer for about 20-25 minutes or until the rice is tender and the liquid is absorbed.
Once the rice is cooked, remove the skillet from the heat and let it rest for a few minutes before serving.