Brown the ground beef with the onions and garlic in a large Dutch oven over medium-high heat until no pink is left in the meat. Drain any grease left in the pot if not using lean ground beef.
Stir in the bell peppers, diced tomatoes, tomato sauce, tomato paste, Italian seasoning, parsley flakes, red pepper flakes, salt, pepper, beef broth, and rice. Bring to a boil.
Reduce the heat, and simmer, covered, for 25 mins or until the rice is tender and cooked through, stirring occasionally so the rice doesn’t stick to the bottom. Remove from heat. If you run out of liquid and the rice is still not tender, add a splash more broth.
Sprinkle the cheese evenly on top and place the lid on until melted, about 5 minutes. If you want a crispy, golden top, place it under the broiler for a few minutes.