Loosely based off from 설렁탕.
- Put bone marrow in boiling water for 10 minutes
- Discard all fat and impurities. Transfer bone marrows to another pot, or wash original pot (it will be very greasy) and put bone marrows back in the clean pot.
- Add enough cold water. Bring to boil, and let simmer for 7-9 hours.
- Leave overnight and let it cool. The next day skim off the thick layer of congealed fat.
You can add root vegetables (onions, radish, carrot, celery, etc).