Start the roux (10 minutes):
In a large heavy-bottomed pot or Dutch oven, melt the butter over medium heat. Slowly whisk in the flour, stirring constantly, until it turns a light brown color (think peanut butter shade). This is the foundation of your etouffee—don’t rush it.
Cook the holy trinity (10 minutes):
Add the onion, green bell pepper, and celery to the roux. Cook until softened, about 7 minutes, stirring occasionally. Add the garlic and cook for another minute.
Build the sauce (5 minutes):
Stir in diced tomatoes, paprika, cayenne, Cajun seasonings, bay leaf, and Worcestershire sauce. Season lightly with salt and pepper.
Add broth and simmer (15 minutes):
Slowly pour in the seafood stock while stirring constantly to avoid lumps. Bring to a gentle boil, then reduce heat and simmer until the sauce thickens, stirring occasionally.
Add the crawfish tails (5 minutes):
Stir in the crawfish tails. Let them cook just until heated through, about 5 minutes. Taste and adjust with hot sauce, pepper to taste, or more Cajun seasoning.
Serve (5 minutes):
Spoon the etouffee over bowls of hot white rice. Garnish with green onions and parsley.