Cut hot dogs lengthwise into quarters then crosswise into thirds.
In a small bowl, combine soup, milk, and salt; stir to blend.
Butter a 2-quart casserole; add sliced potatoes and hot dog pieces. Toss to combine. Add soup mixture. Cover and bake for 1 hour and 15 minutes, until potatoes are tender. Garnish with chopped parsley, if desired.
Calories per serving: 372