Heat a large, 6-quart, wide-mouthed Dutch oven over medium heat. Add the flour and oil to the pan and stir to combine. Cook, stirring constantly, until the flour mixture is a deep chocolate brown color, about 20 minutes. Add the onions, celery and peppers to the roux and cook for 3 to 4 minutes. Add the garlic, stir, and cook the garlic for 1 minute. Add the beer to the roux, stir, and cook for 2 minutes. Add the stock, thyme, bay leaves, 2 teaspoons of Essence, salt, and cayenne to the pan. Stir to combine and bring to a boil. Reduce the heat to a simmer and add the turkey legs to the pan. Cook until the turkey legs are falling-from-the-bone-tender, about 3 hours.
Remove the turkey from the pot and transfer to a plate to cool. Add the collard greens to the pot and cook, stirring occasionally, for 1 hour. When the turkey is cool enough to handle, remove the meat from the bones and tear into bite-size pieces. Discard the skin and bones. Return the turkey meat to the gumbo. Season the shrimp with the remaining 2 teaspoons of Essence and add them to the gumbo during the last 10 minutes of cooking.
Taste the gumbo, re-season if necessary, and add the green onions and parsley to the pot. Serve with steamed white rice.
Combine all ingredients thoroughly.
Yield: 2/3 cup
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch, published by William Morrow, 1993.