Cut the beef into bite-sized pieces and remove any blood.
Slice the radish thickly and cut the green onion into large chunks.
Pour water into a pot, then add the beef and radish. Boil over medium heat.
Skim off any foam (impurities) that forms.
Add garlic, ginger, and green onion, then simmer for at least 1 hour.
Season with salt and pepper to taste.
Serve in a bowl and top with chopped scallions to finish.