Preheat oven to 375°. In large skillet over medium- high heat, cook sausage, stirring to break into small pieces. Drain off any excess fat. In large bowl, whisk together eggs and milk. Stir in sausage.
Oil a 9x13- inch pan. Pour in sausage/egg mixture.
In large bowl combine potatoes and cheese. Add salt and pepper to taste. Spread potato/cheese mixture over sausage/mixture.
In large bowl, mix pancake/waffle mix, water and oil. Pour over potato mixture.
Bake until top is nicely browned and knife inserted off center comes out clean, about 1 hour. Let stand about 5 minutes before cutting squares to serve.
Serve with butter and syrup, or with salsa or catsup.