Preheat oven to 350 degrees. Wash and rinse your turkey under water. Remove giblets and neck if you don't like them. Put turkey in roasting pan.
Separate the skin over the breast meat and put 3 tablespoons (3 slices) of butter on both sides.
In a bowl combine the warm water, chicken bouillon, parsley and onion powder. Pour over the turkey.
Sprinkle seasoning rub all over the turkey.
Distribute carrots and celery in the bottom of the pan.
Put turkey breast side up, cover with foil and cook for 3.5-4 hours or until the internal temperature reaches 170 degrees. Remove the foil for the last 45 minutes.