Brown the meat: Heat the olive oil in a large skillet or Dutch oven over medium heat. Add the ground beef and diced onion. Cook for 5–6 minutes, breaking the meat apart as it cooks, until browned and the onion is tender. Drain excess fat if necessary.
Add the vegetables: Stir in the chopped bell peppers and minced garlic. Cook for 2–3 minutes, until the peppers begin to soften and the garlic becomes fragrant.
Combine the ingredients: Add the diced tomatoes, tomato sauce, broth, uncooked rice, Italian seasoning, paprika, salt, and black pepper. Stir thoroughly so the rice is distributed throughout the mixture.
Simmer: Bring the mixture to a boil. Reduce the heat to low, cover, and simmer for 20–25 minutes. Stir occasionally to prevent the rice from sticking. Continue cooking until the rice is tender and most of the liquid has been absorbed.
Add the cheese: Remove the skillet from the heat and sprinkle the shredded cheddar or mozzarella evenly over the top. Cover for 2–3 minutes, allowing the residual heat to melt the cheese.
Serve: Spoon the casserole into bowls and serve warm. Add fresh chopped parsley on top if desired