Combine oil and flour in large cast-iron or heavy-duty pot over medium heat. Stir constantly while browning. The roux will take approximately 25 minutes to cook. It will become dark brown. If small chips develop, stop and start over. Stir continuously and watch the heat.
Add onions, peppers and cook until they are translucent. Add the sausage and the seasonings and bay leaves. Continue cooking for 5 minutes, stirring often.
Add the water. Stir until all ingredients are well combined. Bring to a rolling boil, then reduce heat to simmer. Simmer for about 1 hour.
Season chicken and add to pot and simmer for 2 hours. Add file powder. Skim any fat that rises to the top.
Serve over steamed rice and garnish with a little chopped parsley.Makes 4 to 6 Source: