Cut up the duck in 8-10 pieces leaving the bones in. Season the duck with the salt and pepper and coat with ½ cup flour.
In a large sauté pan over high heat, heat the oil. Pan fry these pieces until lightly golden and set aside. In the same oil, add the remaining 1 ½ cups flour and stir over medium heat for about 45 minutes until the roux reaches a nice dark brown color. Add the chopped vegetables and the seasonings and stir to combine.
Add the chicken stock and the pan-fried duck pieces and bring to a boil. Be sure to stir this occasionally as it comes to a boil so that the roux does not stick to the bottom. As soon as the gumbo comes to a boil set it at a low simmer. Simmer for 45 minutes to an hour while skimming the oil from the top. Add the Andouille and simmer for another 30-45 minutes or until the duck meat begins to fall off the bone. If the gumbo still tastes of roux, add another pint of stock. If you like okra in your gumbo, now would be the time to add it. Make sure you sauté it first to get some of the sliminess out of it.
Serve with a tablespoon of rice and some fresh chopped scallions.