Preheat oven to 350 degree F. Coat a 1 1/2 quart casserole dish with cooking spray. Set aside. In a large pot,combine water,eggplant, onion,salt and pepper. Bring to a boil over high heat. Allow to boil for 10 to 12 minutes, or until eggplant is tender.
Drain and transfer eggplant and onion to a large bowl. Add soup,milk,egg,stuffing mix and 1 cup cheese. Mix well. Spoon mixture into casserole dish. Sprinkle remaining 1 cup cheese evenly over eggplant mixture. Bake 35 to 40 minutes,or until heated through and edges are golden.