Step 1: Prepare the Roux

1. In a large skillet or heavy-bottomed saucepan, melt the butter over medium heat.
2. Gradually add the flour, whisking constantly to combine.
3. Cook the roux, stirring continuously, until it turns a rich caramel or peanut-butter color, about 8-10 minutes. Be careful not to let it burn.

Step 2: Add the Holy Trinity

1. Once the roux reaches the desired color, add the onion, bell pepper, and celery (known as the “Holy Trinity” of Cajun cooking).
2. Cook for 4-5 minutes, stirring occasionally, until the vegetables are softened and fragrant.
3. Add the minced garlic and cook for an additional minute.

Step 3: Build the Base

1. Slowly pour in the seafood stock, whisking constantly to prevent lumps.
2. Stir in the diced tomatoes (if using), Worcestershire sauce, hot sauce, Cajun seasoning, paprika, and cayenne pepper.
3. Bring the mixture to a simmer and let it cook for 10-15 minutes, stirring occasionally, until it thickens to a gravy-like consistency.

Step 4: Add the Crawfish

1. Gently fold in the crawfish tails, including any crawfish fat for added flavor.
2. Simmer for an additional 5-7 minutes, allowing the flavors to meld together. Taste and adjust seasoning as needed.

Step 5: Serve

1. Spoon the Crawfish Étouffée over a bed of hot white rice.
2. Garnish with sliced green onions, chopped parsley, and a squeeze of lemon juice for brightness.