In a large skillet over medium heat, add the ground beef, breaking it apart with a spatula. Cook for about 5-7 minutes, stirring occasionally, until the beef is browned and no longer pink. Drain any excess fat.

Add the chopped onion, bell pepper, and celery to the skillet. Stir and cook for about 5 minutes, until the vegetables are tender and the onion is translucent.

Stir in the minced garlic and continue to cook for another minute until the garlic is fragrant.

Add the rinsed long-grain rice to the skillet, mixing thoroughly with the vegetable and beef mixture. Pour in the chicken broth and sprinkle in the Cajun seasoning, salt, and pepper. Increase the heat to medium-high and bring the mixture to a boil.

Once boiling, reduce the heat to low and cover the skillet. Let the Dirty Rice simmer for 15-20 minutes, or until the rice is tender and has absorbed the broth.

After simmering, gently fluff the rice with a fork to separate the grains. Taste and adjust the seasoning if necessary. Serve warm.