Naejang-tang (Spicy Mixed Beef Tripe Soup)
Most of the work in this spicy beef offal soup happens before cooking: the mixed tripe is scrubbed with salt and flour into every fold, then soaked in cold water to draw out blood and odor. After a quick blanch the first water is thrown out, and a 50-minute simmer in fresh water softens the thick pieces while building the stock.