Cairo-Style Potatoes with Cumin, Coriander and Cilantro

In Cairo, patates mekhalel are served by street vendors as a side to liver sandwiches, their acidity and spices balancing the richness of the liver. For our version, we peel, cut and cook the potatoes in water seasoned with both salt and vinegar, then dress the hot, just-drained potatoes with additional vinegar. To lightly crush the cumin and coriander seeds, use a mortar and pestle or the back of a heavy pan, or pulse them several times in a spice grinder.