Kimchi is more than pickled cabbage; it's a building block of Korean cuisine that takes many forms. Koryo boasts three incredibly pungent versions, all made on the premises. The familiar cabbage-leaf kimchi, known as paechu, comes packed in chiles but still has a nice crunch. A kimchi of thinly-sliced radish, called nabak or mul kimchi, also provides a satisfying mouthfeel. But the absolute tangiest, zingiest of them all is the gaktugi, the cubed white radish kimchi. The three-quarter-inch cubes come doused in a chile sauce so zippy and fermented that it might remind you of the time you were a kid and put your tongue on a battery. If all of this sounds overwhelming, don't worry. Kimchi has been carefully crafted over the centuries to complement Korean meals. When you've been munching on lettuce wraps filled with white rice, bean paste, and thin slices of barbecue beef, kimchi is the perfect palate cleanser. If you run out while you're still barbecuing your bul go ki, just ask for more. They'll refill your little panchan bowl till you've had your fill.