Linzer, and a Perfect Potato Salad

Preparation

1. Long, pale, and slim, the Linzer Delikatess is as elegant as a tuber could be. I found this Austrian variety at my usual market on a wet day in early July, and brought them home out of curiosity. The flesh was waxy and yellow, and held together well in salted boiling water. They were tender to the knife in ten minutes. Potatoes that keep their shape well in water tend to hold up when saturated with dressing, making them good for potato salads—in this case, a salad dressed with thick Spanish oil, mustard, and dill and tossed with chunks of peeled cucumber. We ate it with a fat, golden-skinned mackerel, smoked that morning by the fishmonger.