Soak the beef short ribs in a large bowl of cold water for about 1 hour to remove impurities.

Chop the onion, garlic, ginger, and green onions, setting aside the green onions for garnish.

In a large stock pot, combine soaked short ribs, chopped onions, garlic, ginger, and 10 cups of water and bring to a boil.

Once boiling, reduce heat to medium and skim off any foam or impurities.

Lower heat to medium-low and let the broth simmer uncovered for 1 hour.

Add the sliced daikon radishes to the pot and simmer for an additional 20 minutes until soft.

Discard the solid aromatics, leaving just the meat and broth, and strain if desired.

Bring broth back to a simmer and stir in guk ganjang, sea salt, and a dash of black pepper.

Ladle the soup into bowls and garnish with freshly sliced green onions and black pepper.