The simple secret to roasting perfect potatoes.
Cover the bottom of a baking dish with a layer of coarse salt. (It does not have to be a thick layer or a complete layer as long as it covers well the place where the potatoes will sit.)
Nestle washed potatoes, skin on, into the salt bed.
Bury the potatoes in more salt, using water to make the salt moldable as necessary, like building a sand castle.
Bake at 400 until fork-tender, about 40 minutes.
The salt can be run through a food processor to break up any chunks and reused.