Prepare the ingredients: Peel the radish and cut it into bite-sized pieces. Clean and slice the garlic cloves.
Purify the oxtail: Soak the unfrozen oxtail in cold water for 1 hour, and the frozen oxtail for 2 hours. Drain the water and refill with cold water every thirty minutes.
Parboil the oxtail: Removing the fat after purifying the oxtail is optional. Transfer the oxtail to a pot, add 2 litres of water, and bring to a boil over high heat for 5 minutes. Thereafter, use a ladle or a scoop to remove the foam and scum from the broth.
Simmer the soup: Add ginger, garlic, bay leaves, and a beef stock cube. Adjust the temperature to low and simmer for two hours with the lid closed. Gently stir the soup every 20 minutes and remove the fat from the surface. Add 1 cup of water whenever the soup is low on liquid.
Serve: Add radish and a handful of spring onions to the pot during the last 30 minutes of cooking. Garnish with spring onions and serve while hot.