Brown the chicken
Melt butter in a large pot over medium heat. Add chicken and cook until lightly browned on all sides, about 8–10 minutes. Remove and set aside.
Make the roux
Add flour to the pot and stir continuously over medium heat until the roux turns a deep brown. This should take about 5–7 minutes.
Cook the vegetables
Add onion, celery, green pepper, and garlic. Cook for 5–7 minutes, until softened.
Build the sauce
Return the chicken to the pot. Add tomato sauce, chicken stock, brown sugar, Creole seasoning, basil, thyme, and bay leaf. Stir to combine.
Simmer
Reduce heat and simmer for 15–20 minutes, until the chicken is cooked through and the sauce has thickened.
Finish
Stir in green onions and simmer for another 5 minutes. Remove bay leaf.
Serve
Spoon over rice and serve hot.
Tip: If your roux starts to smell burnt, start over—it should be deep brown, not black.