Preheat the oven to 400 degrees F.
Cook the potatoes in boiling water until tender, about 20 to 25 minutes. Drain the potatoes, let cool slightly, and then peel. Mix the dressing mix and the cornflakes in a bowl. Dip the potatoes in melted butter, and then roll them in the cornflake mixture. Place the potatoes in a greased baking dish and bake for 20 to 25 minutes, or until golden brown.