Preheat oven 350 degrees. Grease 9 x 13 pan Layer potatoes and 1/2 of cheese in baking dish. Layer ham, mushrooms, green onions and green pepper. Mix eggs, milk, salt and pepper. Pour over layered ingredients. Top with remaining cheese. Bake 30 minutes covered loosely with foil. Remove foil and bake 20-30 additional minutes (once the top in brown, you can put foil back on the top loosely to prevent burning). Let sit 10 minutes before serving.