Given the choice between an hour at an underground luxury spa and a good baked potato, what hungry traveler wouldn’t opt for the spud? As it turns out, a recent tuberous marvel served on a rooftop with a view of the Acropolis was not baked but rather chargrilled, and it did wipe a 20-euro bill and change from my pocket. (Europeans don’t tip, but I do.) More on the potato will follow, because unpacking a most singular setting should come first.