Cut the fish into 2-inch pieces. Season with 1 tablespoon of the Essence and set aside. In a large, heavy stockpot, heat the oil over medium-high heat. Add the flour and stir constantly with a heavy wooden spoon until it becomes a dark roux the color of chocolate, about 15 to 20 minutes. Add the celery, onions and bell peppers, and cook, stirring, until the vegetables are wilted, 6 minutes. Add the bay leaves and garlic, and cook for 2 minutes. Add the tomatoes, wine, stock, salt and cayenne, and stir well. Bring to a boil and reduce heat to medium-low. Simmer uncovered, stirring occasionally, until thickened, about 30 minutes. Add the fish and cook until it flakes with a fork, about 10 to 15 minutes. Stir in the green onions and parsley during the last 5 minutes of cooking time. Remove the bay leaves and serve hot in soup bowls ladled over rice.
Combine all ingredients thoroughly and store in an airtight jar or container.
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch. Published by William and Morrow, 1993.