Dried curd in Ulaanbaatar market. It's a Mongolian treat and a staple also across the central Asian and Caucasian regions too, from Turkey to Mongolia. Variously known as kashk, qurt, qurut, kurut, sürk, chor - and in Mongolian, aaruul. Generally made from drained yogurt or drained sour milk. It's formed and dried and sold in slices, blocks, chunks and other forms. As one can see there's heaps of it (literally) around.