'Qurut', the dry yogurt ball, rich in calcium and protein, which has been chewed since the time of Genghis Khan. Óscar López-Fonseca invites us to explore the kitchens of the world with culinary experiences that, surely, the father of the theory of evolution would have ventured to try on that trip.

The balls are called qurut or qurt in Kazakhstan, Uzbekistan and Tajikistan; chortan in Armenia; kurut in Kygyzstan.