The slow-cooked dark roux is the cornerstone of this wonderful one-pot dish. All of the ingredients build on the flavor of the roux as each adds another layer of divinely rich taste in this classic New Orleans dish.
Put chicken pieces in a bowl. Mix chicken with salt, black pepper, cayenne pepper, paprika, garlic powder, onion powder and celery salt. Set aside.2.
In a heavy-duty Dutch oven over medium heat, add the canola oil and flour and stir constantly until the roux turns a deep brown color, like milk chocolate. It is very important you stir constantly, or the roux will burn. The whole process should take about 20-30 minutes, so be patient and get a good color to your roux in order to achieve an authentic Cajun gumbo.3.
Add the seasoned chicken to the hot roux and stir for 3 more minutes.4.
Add the chopped onion, celery and green pepper to the roux and stir to blend well.5.
Add the chicken broth, diced sausage and bay leaves; bring all to a simmer. Once the liquid is simmering, reduce heat to low and cook for 45 minutes.6.
Remove gumbo from the heat and ladle into serving bowls.7.
Top each bowl with a large spoonful of white rice or potato salad and sprinkle a 1/4 teaspoon of file over the top, as well as a pinch of chopped scallions.