Toss chicken with ½ tablespoon Creole seasoning.
Melt 1 tablespoon butter in a large Dutch oven over medium heat. Add chicken. Cook, stirring occasionally until all pink is gone, about 5 minutes. Remove chicken from Dutch oven; wipe Dutch oven with paper towel.
Melt remaining 4 tablespoons of butter in Dutch oven over medium heat. Add flour and stir continuously until the roux is the color of peanut butter, 6 to 7 minutes. Add onions, celery, bell pepper, and garlic to the roux. Cook, stirring often, for 10 minutes. Add petit diced tomatoes, salt, and remaining ½ tablespoon of Creole seasoning. Cook mixture for 2 to 3 minutes.
Add chicken broth. Bring mixture to a boil over medium heat, stirring constantly, until thickened. Reduce heat to low; simmer uncovered, stirring occasionally, for 30 minutes. Can be made in advance up to this point.
Heat Étouffée over medium heat. Add the chicken. Cook 15 minutes, or until vegatables are tender and chicken is thoroughly heated.
Serve over cooked white rice; garnish with sliced green onion tops. Yield: 4 to 6 servings. (See Tip 3)