Soak the beef short ribs in cold water for about 1 hour to draw out excess blood and impurities. Drain and set aside.

Prepare the aromatics by slicing the onion, fresh ginger, and chopping garlic. Set aside.

Combine the soaked beef short ribs and prepared aromatics in a large stock pot. Pour in 10 cups of water.

As the broth comes to a boil, skim off the foam that rises to the surface. Reduce heat to medium-low and cover slightly.

Let the broth simmer uncovered for 1 hour to develop rich flavors. Skim off any additional foam if needed.

After 1 hour, add sliced radish to the pot and continue simmering for another 20 minutes until tender.

Remove whole aromatics and season the broth with guk ganjang, sea salt, and extra chopped garlic.

Simmer the soup for an additional 10 minutes before serving. Ladle into bowls and garnish with green onions and black pepper.