I think by far rice and gravy. It's relatively simple to prepare compared to a gumbo and absolutely delicious. There was a time in my mom's life when she made rice and gravy every single day.
Large bottom round steaks, four or five pounds of the stuff, are browned at high heat in oil until almost burned, then braised in a dutch oven in onions, bell peppers, and water until fork-tender. Brown them individually, pull them out of the oil and let it get hot again before adding the next steak.
These days my mom cuts the steak into strips as this increases the surface area of the browning so as to make a richer gravy. Added bonus is you don’t have to pull the steak out so it goes a bit quicker. But traditionally the steaks were kept round and whole, and it was the mark of a good chef when you could manage to keep them fork tender yet still intact. You'd break off as much meat as you wanted when making your plate with nothing more than a fork. Season the outside with lots of Tony Chacherie’s. Don’t skimp on the Tony’s. There’s not a good opportunity to season it later.
Use plenty of oil. Don't try to make this dish healthy, you'll just be missing out on the insane flavor. It’s not even worth it, just go make chili or something. After your steaks are brown, add water to cover and simmer until the meat is tender and the gravy thin but phenomenally rich.
Another common dish is rice dressing, which stands on its own as a main dish but is usually served on the side. A mixture of ground beef and pork, one part pork to three parts beef, is browned in oil, onions and green bell peppers. Don't use red, only rich New Orleans folks could get red bell peppers so Cajuns never learned how to use them. Green peppers, always in Cajun food.
There is a technique to browning ground beef the Cajun way. In fact, you can make almost anything Cajun with this technique, so long as you don't introduce any weird ingredients, like herbs or carrots. Be careful with celery and garlic. They don't belong in most Cajun dishes.
Anyway, first you must season your ground beef. This is done with Tony Chacheries spice mix, available in most grocery stores across the country. Do not attempt to make your own mix or use off brand chicanery. Cajun grandmas didn't have time for such frivolities. They needed all the time they could get to stir roux.
It takes a good ten minutes to season ground beef. Sprinkle Tony's liberally on your meat in a mixing bowl. Mix. Repeat until your meat no longer has that ground beef smell. Tony's is cheap as dirt, don't be stingy. Buy extra cans. You'll use it, trust me. It's basically ground bulk sausage when you're done. Don’t even think about your blood pressure from all that salt. Embrace being fat and happy like 99% of Cajuns. The diabetes is totally worth it.
Get your dutch oven, I like the enameled ones, much easier to clean, and heat a goodly amount of oil, at least three glugs. Let it get really hot. The key to browning ground beef is to never let the oil get too cold. Then the beef just won’t fry properly. Once hot, start slowly adding pieces of ground beef you break off with your fingers. Don’t go too fast, don’t go too slow. You want your beef to be almost burnt, very gray, before you add water.
Add your chicken livers. My mom likes to devein these and chop them finely. I don’t bother cleaning them and like a more course chop, it’s easier and little bits of liver in the end product gives it that little extra something, but some people don’t like it. I just use the whole container, there’s usually 6–8 livers in there, plenty. I usually do three pounds of ground beef and one of pork. My mom’s a bit more careful with her measurements but she grew up with the stuff so she’s way more sensitive to differences. She’ll use fewer livers than just because I don’t want to mess with a extra liver sitting in my fridge waiting to me to find a use for it or court diabetes with another batch.
Add water to cover and let it cook for a few hours. Take note here about what’s I’m giving explicit instructions for and what I’m not. This isn’t a fussy dish, so long as you get what’s important about it right. Brown your well-seasoned meat in oil, until just-shy-of-burnt, deglaze with water. Use chicken livers and don’t add silly spices or herbs. Don’t add too much meat at one time to the hot oil. That’s what’s important. How much meat you add and how long you cook is less important.
Add small amounts of water to keep the level from getting too low. When you’re done cooking turn off the burner. Take the rice you made earlier in the day and let cool on the counter and start adding small amounts. Long grain rice only, we’re not making risotto. Don’t just make a batch of rice and put hot rice in. It’ll break down while you’re mixing it and ruin the texture. You want it to stay firm, not get mushy.
How much rice you put in is a matter of taste. Some like wet rice dressing, some like it more dry. Go to Popeyes or Churchs and get an order of Cajun rice to get a good idea of what it looks like. I prefer a wetter rice dressing, and will add water to it when making leftovers to fluff it back up. This is a dish that often benefits from a night or two in the fridge to let the flavors get all intimate with each other. However much you use, add it slowly and make sure it’s incorporated before adding more. It’s a lot of stirring, which is why you need cold rice. This is what it looks like:
Enjoy your brand new addiction! Make it by the instructions first so you can experience the awesomeness of 300 years of French-American history before adding non-Cajun ingredients.