I find Desiree potatoes AL THE TIME at the Stockengut Farm in Kilchberg (
http://www.stockengut.ch/) they are wonderful and tasty, always ust freshly picked from the ground. If you have a car, it's easy to get to!! Just right over the zürich/kilchberg boarder and up the hill! If you have kids, it's a great place to visit and then drink some fresh milk from the cows afterwards, or freshly made Süssmost!