500g flour 3g salt 160g hot water 160g cold water (400g flour is ok) Cut to small pieces （ as small as possible)and brush oil for 40min 500g ground beef 50g pepper water 10g sesame oil, one table spoon 生抽， less than half spoon 料酒, half table spoon 老抽 leave for 40mins then add Onion, green onion, ginger