Wash potatoes and slice thin with skins on. (like scalloped potatoes). Cut hot dogs in 1/4 to 1/2 inch pieces. Slice onion thin.
In a casserole dish, layer 1/2 of the potatoes, 1/2 of the hot dogs and onion, then layer the other half of potatoes and hot dogs. Mix cheese soup with milk and salt/pepper. Pour over top of potatoes and hot dogs. Drain can of corn and pour on top of casserole (optional).
Cover and cook at 375°F for 1 hour or until potatoes cooked.