Cook zucchini and onion in lightly salted water until crisp tender (about 5 minutes); drain; prepare gravy mix, combine with water chestnuts, carrots, sour cream and the zucchini/onion mixture.
Combine stuffing mix and butter. Spread half in bottom of shallow 2 quart casserole. Top with vegetable mixture and sprinkle with remaining stuffing. Bake at 350 degrees for 25-30 minutes.
Adapted from America's Country Inn Cookbook (The R.T. French Company) by Loren Martin, Big Cabin, Ok