Place a large skillet over medium-high heat and introduce the ground beef, chopped chicken gizzards, and diced green bell pepper. Brown the meat thoroughly, breaking it apart as it cooks, and continue until no pink remains. Drain any excess grease, if necessary.
Lower the heat to medium-low and incorporate the green onions, Creole seasoning, garlic powder, celery flakes, ground black pepper, red pepper flakes, and beef broth into the skillet. Stir to blend the flavors.
Add the cooked long-grain rice to the mixture and stir until evenly combined. Allow the dish to simmer gently for 10 to 15 minutes, stirring intermittently, until the liquid has evaporated.
Taste and adjust the seasoning with additional Creole seasoning, salt, or red pepper flakes as preferred. Serve while hot.