Heat oven to 350°F. In 10-inch skillet, melt butter over medium-high heat. Cook onion in butter 2 to 3 minutes, stirring frequently, until tender.
In large bowl, toss stuffing, onion mixture, water and corn until stuffing is moistened. Stir in cheese.
Into 13x9-inch pan, spoon stuffing mixture. Arrange pork on stuffing mixture. Cover pan with foil. Bake 40 to 45 minutes or until cheese is melted and meat thermometer inserted into center of pork reads 160°F.