Empty contents of stuffing box, both the bread crumb and seasoning envelopes, into a medium bowl.
Add hot water and butter; stir to mix.
Add chopped water chestnuts, onion and poultry seasoning, mix thoroughly and set aside.
Check inside the chicken for giblets, remove and set aside.
Rinse chicken inside and out with cold running water.
Dry thoroughly inside and out with paper towel.
Sprinkle salt and fresh ground pepper inside the cavity and all over the outside.
Place chicken in a roaster.
Loosely pack the stuffing mix into the main cavity and any left into the neck cavity folding the skin over it.
If necessary secure the neck skin with a pick.
Take a length of kitchen string and tie the ends of the legs as close together as possible.
Rub the butter all over the outside of the chicken making sure to cover the whole outside surface.
Take two lengths of aluminum foil, place one piece over the chicken lengthwise, take the other piece and place it sideways over the first piece.
Tuck the foil tightly to the chicken so it is touching the bottom of the roaster but not under the bird.
If the bird is not completely covered (except for the underside) Use a third piece to finish covering.
Place the roaster on the middle rack of the oven and roast at 400f degrees for 15 minutes.
Reduce the heat after 15 minutes to 350f degrees and roast for approximately 2 hours.
At about 2 hours, carefully lift the aluminum foil and poke the chicken with a fork, if the juice runs clear, remove the foil and roast a further 30 minutes to brown the skin to golden.
If the juice is not yet clear, roast a little longer and check again.
Once the chicken is well browned, remove to platter, cover with foil and let rest.
In the meantime, if you wish to make giblet gravy, take the giblets (and neck if it's there), place in a saucepan, cover with water, add salt and pepper and a little poultry seasoning if you wish, bring to boil, reduce heat and simmer for at least an hour.
Remove to strainer, reserving liquid.
Chop the giblets and pick any meat off neck bones, add to a blender and add the liquid.
Blend to liquefy level, add 3 or 4 tablespoons flour or corn starch and blend to mix well.
Pour off as much fat as possible from the roaster, take a whisk and move up any bits and pieces of stuffing/chicken stuck to the bottom, remove any large pieces of skin, add the giblet mix from the blender, whisk around; place in 450°F to 500°F degree oven until bubbly, about 10 minutes; add a small amount of hot water if necessary if it is too thick until it is the consistancy you want, cook another 5 minutes.
(We like ours very thick) Whisk and pour into gravy boat and serve hot with the roast chicken.
Gravy can also be made without the giblets, just whisk up the brown bits in the roaster and add 1 cup of hot water and make a slurry of cold water and either flour or corn starch, add the slurry and whisk, cook the same as above adding a little more water if necessary.