Start by melting the butter in a large skillet or pot over medium heat. Stir in the flour gradually and keep stirring non-stop. Within 5–7 minutes, it’ll darken into a rich, coppery roux. Don’t rush this part—it’s the backbone of the whole dish. I’ve learned to be patient and never stop stirring!
Once your roux is ready, toss in the diced onion, celery, bell pepper, and garlic. Let them cook down in that flavorful roux for about 5 minutes, until they’re softened and fragrant. This step really brings the dish to life—I always love the way it smells at this point.
Now it’s time to season. Add Cajun seasoning, cayenne, salt, and black pepper to the pot. Pour in the chicken or seafood stock slowly, stirring well so the mixture stays smooth. Bring it to a gentle boil, then reduce the heat and let it simmer for about 20 minutes. This is where the magic happens—the sauce thickens and all those flavors blend beautifully.
Fold in the crawfish tails and let them heat through for 3–5 minutes. Since they’re already cooked, you just want to warm them gently without making them rubbery. I always stir carefully here to keep the tails intact and tender.
Turn off the heat and stir in the chopped parsley for a fresh, bright finish. Spoon generous portions over warm white rice and serve immediately. I like to top mine with more parsley and a dash of hot sauce—it looks great and tastes even better!