Cut the chicken and sausage into bite sized pieces.
Heat a dutch oven over medium heat and add the sliced sausage. Cook until brown on the outside, about 5 minutes. Remove and set aside.
Add the chicken to the same pot and brown on the outside, about 3 minutes per side. Remove and set aside and turn off the heat.
Use a paper towel to wipe out any excess liquid from the dutch oven.
Turn the heat to medium low and add the flour and oil to the dutch oven. Cook, whisking constantly, for about 10 minutes, or until the roux is golden brown in color.
Add the chopped onion and green pepper and cook for about 2-3 minutes.
Add the tomatoes and stir in.
SLOWLY add the stock in, stirring constantly while adding to ensure the roux doesn't break.
Add the okra, bay leaf, Cajun seasoning, Worcestershire sauce and sugar and bring to a simmer. Cook at a simmer for 5 minutes.
Add the chicken and sausage and simmer for 5 minutes.
Remove from heat and stir in the gumbo file. Serve with steamed white rice and crusty French bread.