Authentic dirty rice contains chicken livers, but don't fret if you don't like them. Follow this recipe, but increase the beef or pork and you'll have a wonderful basic undirty Cajun Rice.
Cajun Dirty Rice
There are as many dirty rice recipes as there are southern cooks, but authentic dirty rice recipes always include chicken giblets of some kind - usually livers, though the kidney, heart and gizzard are often used as well.
This is just one of those Cajun dishes that was born out of the tradition of using every part of the animal in meals.
Also, when we cook rice in the south, which we do regularly, we tend to cook a bunch so that there's just about always some rice hanging around in the fridge. This dish is a great way to use some of that leftover rice, which I feel surely must've had something to do with its creation in the first place.