Although fried chicken in a soy/vinegar  sauce has been around for hundreds of years in South Korea, the modern version became popular in South Korea in the 1960s. It would then make the jump across the Pacific in the late 70s. At its most basic, Korean Fried Chicken is crispy chicken tossed in a spicy sauce usually made with goguang paste. This sandwich has quickly become one of my favorite sandwiches.