1Heat oven to 400ºF.
2Cook beef in 10-inch skillet over medium heat 8 to 10 minutes, stirring occasionally, until brown; drain. Stir together Potatoes, Sauce Mix, boiling water and milk in ungreased 2-quart casserole. Stir in beef and 1/2 cup of the cheese.
3Bake uncovered about 30 minutes or until top is light golden brown. Sprinkle chips over casserole; sprinkle remaining cheese over chips. Bake 5 minutes longer or until cheese is melted. Let stand 2 minutes before serving.