Seolleongtang

Method

1. Put 300 g of ox leg bones in a bowl, cover generously with cold water and soak for 2 hours, changing the water twice. The water should run pale pink rather than red — this is what keeps the finished broth clean and white.
2. Drain the bones, put them in a large pot, cover with fresh cold water and bring to a rolling boil over high heat. Boil hard for 10 minutes, then tip the whole lot into the sink. Rinse each bone under running water to remove the grey scum and scrub the pot clean before going on.
3. Return the rinsed bones to the clean pot with 2 litre of water. Bring to a hard boil over high heat and boil uncovered for 30 minutes, skimming the foam and fat off the surface, then lower to a steady, lively simmer and cook for 3 hours. Top up with hot water whenever the level falls below the bones — the constant agitation is what emulsifies the collagen and turns the broth milky.