Measure and chop the onion, celery, green pepper, parsley, and green onions. Mince the garlic. Thaw and drain crawfish tails if frozen; pat dry with paper towels. Have chicken stock and rice ready.

Make the roux

In a heavy-bottomed skillet or Dutch oven over medium heat, melt 6 tbsp unsalted butter. Add 6 tbsp all-purpose flour and whisk constantly to combine. Continue to cook, whisking frequently, until the roux turns a light to medium brown and develops a nutty aroma, about 6–8 minutes. Reduce heat if it begins to darken too quickly.

Cook the vegetables

Add the diced onion, celery, and green bell pepper to the roux. Stir to coat and cook over medium heat until the vegetables are softened, about 6–8 minutes. Add the minced garlic and cook 30–60 seconds until fragrant.

Build the base

Stir in 1 tbsp tomato paste and cook 1 minute. If using, pour in 1 tbs dry white wine and let it simmer 1–2 minutes to reduce slightly. Slowly whisk in 2 cups low-sodium chicken stock, a little at a time, ensuring a smooth sauce without lumps. Add 1 tsp Worcestershire sauce, 1 tsp hot sauce, 1 tsp Creole or Cajun seasoning, 1 tsp paprika, 1 tsp dried thyme, and 1 bay leaf. Bring the mixture to a gentle simmer and let it thicken for 6–8 minutes, stirring occasionally.

Add crawfish and finish

Stir in 1 lb crawfish tails and simmer gently for 4–6 minutes, until heated through and flavors meld. Taste and season with 1/2 tsp salt and 1/2 tsp coarsely ground black pepper, adjusting to preference. Remove from heat and stir in 1 tsp fresh lemon juice, 2 tbsp chopped parsley, and 2 tbsp sliced green onions.

Serve

Spoon cooked white rice into bowls or cups (about 1 cup rice per serving). Ladle the crawfish étouffée over the rice. Garnish with additional parsley and green onions if desired, and pass extra hot sauce at the table.