What is the purpose of the bed of salt to roast the potatoes on, like does it actually season the potatoes or something else...? Thanks!

I know America's Test Kitchen did a bit on their show about this technique, and I gave it a shot. I will admit it did change the texture of the russets for the better, but season them? Not so much, in my opinion. One difference between their method and this recipe though, ATK had their spuds bake covered with foil. Now one thing that baking has in it's favor, especially considering you are making gnocchi, is that it's a dry cooking method. So your potatos won't be ending up waterlogged, or in need of off steaming to hopefully dry some. When I make potato gnocchi, I always bake my potatos. Just not always on a salt bed. In fact, seldom on a salt bed- because I honestly don't feel like consigning 2 or more cups of salt. Yeah, you can use it over again. But I don't do that very often, and the salt just ends up in a container taking up space on the shelf. Your call, really. The point is to have dry flesh to work with, and baking with or without salt will get you that a lot more likely than boiling will.