Koprovka

Dill sauce with potatoes and eggs

Summer in a Czech garden means dill gone wild between the cucumbers, and koprovka is where most of it ends up. This pale green, gently sour cream sauce is a staple of Bohemian home cooking and of workplace canteens, where it is served over boiled potatoes with halved hard-boiled eggs (or with bread dumplings). It should be smooth, silky and only lightly thick, balanced between cream, a little vinegar and a pinch of sugar. Where it usually goes wrong is boiling the dill: it turns grey and loses its fresh smell, so stir it in at the end, off the heat. Chef's tip: keep the dill stalks, chop them very finely and simmer them in the sauce, then add the soft fronds at the end for a double hit of flavour.