Put bread cubes in large bowl and break into small pieces.
Add chicken stock or water to soften bread.
In a frying pan, melt butter on medium-high heat, add chopped onions and celery. Sauté until soft, about 5 – 7 minutes.
Add the salt, poultry seasoning and eggs to the softened bread and mix well.
Mix onion & celery mixture into bread pieces and spoon into an 18 – 20 lb turkey and roast for 15 minutes per pound of turkey until internal temperature is 165ºF.
Leftover stuffing can be baked in a 9" x 13" pan for 50 – 60 minutes.