Add the vegetable-roux mixture to the slow cooker.
Add the Creole seasoning, thyme, and cayenne pepper. Stir well.
Pour in the chicken broth and add the sliced sausages, seasoned chicken pieces, and bay leaves.
Cover the slow cooker and cook on low for 6-8 hours or high for 5-6 hours.
Serve over hot cooked rice and garnish with green onions and parsley. Add a pinch of gumbo filé powder to each serving, if desired.