This beef jerky, called yukpo in Korean, is a traditional Korean recipe and considered to be very precious food. Not only is beef expensive in Korea, but the process of making yukpo takes time and care. In the old days yukpo was sun and wind dried, which meant that you had to look after it for days while it sat out in good weather. Its traditionally one of the wedding day gifts from the brides mom to the grooms mother and father.In modern times, a food dehydrator makes the job much easier, but this is still a very precious food. The process is easy but you still need to take care to do it right. Use lean and flavorful beef, and slice it thinly along the grain. You can use beef flank steak, top round, bottom round, or eye of round, just be sure to use the cut that has the least amount of fat. But a tiny amount of fat in the meat makes it more flavorful. Korean yukpo is traditionally marinated in soy sauce, but I found that just a bit of liquid smoke makes it extra tasty, and some crushed chili flakes makes it spicy.