In a large bowl, combine the stuffing mix and melted butter . Set aside 1/2 cup of stuffing mixture for the top of casserole.
In a large bowl add the zucchini, cauliflower, chicken, chicken soup,onion, green chilis, mushrooms and sour cream to the remaining stuffing bowl. Place the zucchini mixture into a 9x13 greased glass dish and spread evenly.
Sprinkle reserved 1/2 cup of stuffing mix on top and bake uncovered at 350°F for 40-50 minutes or until golden brown.