Bugeoguk 북어국
This is such a simple, light and tasty soup. You need good quality wind-dried Alaska pollock, pre-shredded. I bought a packet in Korea, but sadly I just finished the whole packet. I'm sure this will be available outside Korea. The Korean name of the fish is myeongtae (명태).
Tear 60 grams of dried pollack into 6 cm long pieces (this just means halving the pre-shredded pollack) and fry these for a minute or so in a tablespoon of pure sesame oil with a couple of diced cloves of garlic.
Add 1,25 litter of water to the pan and Korean radish (mu 무) cut in bite sized pieces. Boil for 20 minutes until the radish is cooked. Add 2 tablespoons of Korean fish sauce, simmer for a couple of more minutes. Pour a beaten egg into the boiling soup and only stir after the egg has set. Turn off the heat and add fresh spring onion. Serve with white rice, which you can add to the soup halfway for a more substantial meal.
You can also make a somewhat similar soup with hwangtae, made by drying Alaska pollack during winter and allowing it to undergo natural freeze-thaw cycles.