Are these the purple, freeze dried potatoes made in the Andes mountains called Chuno? I hate chuno numerous times while in Bolivia but I certainly wouldn't say that they taste the same as regular potatoes (the ones I'm thinking of)
Wouldn't mind finding some chuno as well as recipes to use with them.
Another purple potato that has a very nice flavor are Okinawan Sweet Potatoes. We use them for the starch in certain dishes and they add an interesting color and flavor to gnocchi, potato filled ravioli, etc.
I remember using purple puruvians in a cooking class i went to once. We roasted them with two other kinds of potatos. I dont really remember the recipe totally but it was pretty simple. We just took purple puruvians, yukon gold and one other kind sorry i cannot remember, and cut them in half. Then we just drizzled on some olive oil, tossed them with salt, pepper, thyme and rosemary and voila, a ice little version on roasted potatoes.