Place the cubed potatoes in a 3 quart saucepan and cover with cold water. Bring to a boil; reduce heat and simmer until the potatoes are just barely tender; drain and quickly rinse with cold water. For the sauce, combine soup mix with milk in a saucepan; whisk until smooth. Heat over medium heat, stirring frequently, until sauce is thickened. Stir in the cheese – reserving a handful for garnish. Combine the cooked potatoes and the cheese sauce; place in a greased 3-quart baking pan. Refrigerate for up to 2 days. Bake, uncovered, at 350° until heated through – or up to 1 hour. Cover top with foil if the potatoes start to brown. Top with cheese and bacon to serve. Makes 10-12 servings.