step 1
Fill a large pot with water and add the beef and bone marrow if using. Over a medium heat. Bring to the boil. Skimming the scum that floats to the top untill the broth is clear.
step 2
Add the stock cube, onion, peppercorns and fish sauce. Lower the heat to a simmer. Cover and cook for about 1 to 1 and a half hours. Or until the the beef is tender. Keep an eye on the the water level. Add more if needed.
step 3
Once beef is tender, add the green beans. Cook for 5-7 minutes.
step 4
Add the leek and cabbage. Cook for a further 5 minutes until the vegetables are cooked. Season to taste.
step 5
Serve over a bowl of boiled rice.