In a large pot over a medium heat melt the butter and add in the flour. Cook the roux over a medium heat stirring consistently until it turns to a beautiful caramel color.
Add the onion, garlic, celery, and green pepper into the roux and saute for 5 minutes until the vegetables are beautifully fragrant.
Pour the crushed tomatoes, chicken stock, bay leaves, and creole seasoning into the pot. Stir then cover and cook for 20 minutes, until thickens. Be sure to stir it every now and again.
Cut the chicken breasts into cubes and then add it to the pot once the stew has thickened. Stir the whole thing and cook for 10 minutes.
Remove the bay leaves and sprinkle over the green onions before serving.