How to make churpi? Hardest cheese in the world

Chhurpi (Nepali: छुर्पी, Tibetan: ཆུར་བ།) or durkha is a traditional cheese consumed in the Himalayan regions of Nepal, Sikkim, Darjeeling, Kalimpong, Bhutan, and Tibet. The two varieties of chhurpi are a soft variety (consumed usually as a side dish with rice)[3] and a hard variety (chewed like a betel nut). It is known to be native to Tibetan cultural areas, spreading to Nepal and India.