1. Brown the ground beef in a large deep skillet with the olive oil over medium-high heat, breaking it into crumbles until no pink remains. Stir in the chopped chicken livers if using and cook until browned, then drain off excess fat, leaving a thin layer in the pan.

2. Add the diced onion, green bell pepper, and celery to the skillet and sauté until softened and lightly golden, about 5 to 7 minutes. Stir in the minced garlic and cook just until fragrant.

3. Stir in the rinsed long-grain rice, coating it in the pan juices and vegetables, and toast for 1 to 2 minutes while stirring frequently so it does not stick.

4. Sprinkle in the Cajun seasoning, smoked paprika, dried thyme, dried oregano, cayenne pepper if using, kosher salt, and black pepper, stirring until the rice and meat are evenly coated in spices.

5. Pour in the low-sodium chicken broth, scraping up any browned bits from the bottom of the skillet, and bring the mixture to a gentle boil.

6. Reduce the heat to low, cover the skillet with a tight-fitting lid, and simmer for 18 to 20 minutes, or until the rice is tender and the liquid is absorbed.

7. Remove the skillet from the heat and let it rest, covered, for 5 minutes. Uncover, fluff the rice with a fork, and stir in the chopped fresh parsley and half of the sliced green onions.

8. Taste and adjust seasoning with additional salt, pepper, or Cajun seasoning as desired, then serve hot topped with the remaining green onions.