In a large enameled cast iron Dutch oven or large pot, heat 1 tablespoon of the vegetable oil over medium-high heat. Add the sausage and cook until well browned, about 8 minutes. Remove the sausage with a slotted spoon and drain on paper towels. Set aside.
Season the chicken with the Essence and add in batches to the fat remaining in the pan. Cook over medium-high heat until well browned, 5 to 6 minutes. Remove the chicken from the pan, let cool, and then refrigerate until ready to use.
Combine the remaining 1/2 cup oil and the flour in the same Dutch oven over medium heat. Cook, stirring slowly and constantly for 20 to 25 minutes, to make a dark brown roux, the color of chocolate.
Add the onions, celery, and bell peppers and cook, stirring, until wilted, 4 to 5 minutes. Add the reserved sausage, salt, cayenne, and bay leaves, stir, and cook for 2 minutes. Stirring, slowly add the chicken stock, and cook, stirring, until well combined. Bring the mixture to a boil. Reduce the heat to medium-low and cook, uncovered and stirring occasionally, for 1 hour.
Add the reserved chicken to the pot and simmer for 1 1/2 hours, skimming off any fat that rises to the surface.
Remove the pot from the heat. Using a slotted spoon, remove the chicken thighs from the gumbo and place on a cutting board to cool slightly. Remove and discard the bay leaves. Pull the chicken meat from the bones and shred, discarding the bones and skin. Return the meat to the gumbo and stir in the green onions, parsley, and file powder.
Spoon rice into the bottom of deep bowls or large cups and ladle the gumbo on top. Serve, passing hot sauce on the side.
Emeril's ESSENCE Creole Seasoning (also referred to as Bayou Blast):
Combine all ingredients thoroughly.
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch Published by William and Morrow, 1993.
Yield:Inactive Prep Time: 5 minutes
In a 2-quart saucepan, combine the rice, water, butter, salt, and bay leaf and bring to a boil over high heat. Reduce the heat to low, cover, and simmer until all the liquid is absorbed, about 20 minutes. Remove the pan from the heat and let sit, covered and undisturbed, for 5 minutes.
Uncover and fluff the rice with a fork. Discard the bay leaf and serve.