Begin by gathering your ingredients for Dirty Rice. Chop the onion, green bell pepper, and celery into small pieces, and mince the garlic.

In a large skillet, heat up a tablespoon of vegetable oil over medium heat. Once hot, add the ground beef, breaking it apart with a spatula. Cook for about 5-7 minutes until the meat is browned.

Add the chopped onion, bell pepper, and celery to your skillet. Sauté these vegetables for about 5-7 minutes until they become tender. Stir in the minced garlic and cook for an additional minute.

Sprinkle Cajun seasoning over the sautéed mixture. If using, add diced tomatoes and let simmer for 2-3 minutes.

Gently fold in the cooked rice into the beef and vegetable mixture in the skillet. Cook together for 3-5 minutes, allowing flavors to meld.

Remove from heat, transfer to serving bowls, and garnish with chopped parsley or green onions. Serve hot.