Wash the beef shank thoroughly and cut it into large pieces.
Prepare the onion, green onion, and garlic.
Pour water into a pot and bring it to a boil.
Add the beef shank and aromatic vegetables to the boiling water.
Skim off any foam, reduce to low heat, and simmer for 1–2 hours until tender.
Remove the cooked beef shank and cut it into bite-sized pieces.