Rinse the chicken and remove the giblets. Stuff the cavity with as much of the fennel, celery, parsley stems, orange, rosemary, and garlic as will fit inside the cavity. Season the outside of the chicken with salt and Creole seasoning or pepper.
Put the chicken breast side down on a broiler pan with a rack and set it in the center of the oven. Reduce the oven to 350 degrees.
Roast for one hour, and check the temperature of the chicken with a meat thermometer. When it reaches about 170 degrees, turn the oven up to 450 degrees, and put very small slivers of butter all over the outside of the chicken.
Roast another five to ten minutes. Check to make sure the juices run clear from the thigh. Remove from oven and let stand for fifteen minutes before serving.
