Method:

Step 1 – Make the Roux
Heat oil in a Dutch oven over medium heat. When the oil gets hot, whisk in flour. Continue whisking until the roux has cooked to the color of dark chocolate, 10 to 12 minutes. You must stir constantly. Be careful not to burn the roux! You will have to start over if you see black specks in the mixture!

 Step 2
Stir the onion, bell pepper, celery, and sausage into the roux and cook down for about 5 minutes, or until the vegetable are clear and soft. Stir in the garlic and cook another 5 minutes. Season with salt, pepper, and Creole seasoning; blend thoroughly. Pour in the chicken broth and add the bay leaf. Bring to a boil over high heat, then reduce heat to medium-low, and simmer, uncovered, for 1 hour, stirring occasionally. Stir in the chicken, and simmer 2-3 hours. Skim foam that floats to the top during the last hour.