In your Dutch Oven or Slow Cooker whisk together the flour and oil and cook the mixture over low to medium heat for 15 minutes or until the roux turns golden brown. You will notice that the roux will begin to have a nice toasty smell when it is ready.
Next stir in your onions, celery, bell peppers, diced tomatoes, garlic, and all of the spices (creole seasoning, chili powder, cayenne, basil, oregano, thyme, ground pepper and kosher salt)
Cook the veggies, spices and roux on medium heat for 5 minutes, stirring occasionally until they begin to soften. Note, do not brown.
Next add the broth, chicken and diced sausages.
If you are using a Dutch Oven bring the gumbo to a boil and reduce the heat to low letting the gumbo cook for at least three hours or until the chicken falls apart. You can also move the gumbo to the oven (325 degrees) and let it cook in the Dutch oven for 3-4 hours. If you make this the day before simply reheat the gumbo while making the rice.
Note if you are using a crock pot cook on low for 6-8 hours and switch to high heat the last hour so the gumbo thickens. I usually turn the slow cooker to high as I prep the rice and prepare for dinner.
Serve with Rice and top with fresh Parsley and Basil. I like to add some cornbread or a nice slice of bread and a salad to round out the meal. Enjoy!