Wash and cut beef into cubes. Chop 1/4 of the onion and slice the rest of it. Chop garlic and ginger and grind the mustard fine.
Add all the above ingredients except coconut milk, mustard, sliced onions, curry leaves and oil. Bring to a boil and cook till meat is tender. Add a little bit of water if desired.
Now mix mustard with coconut milk and add to meat, bring to boil and remove from fire.
Then heat oil in a pan and when very hot add the curry leaves and sliced onions and fry till crisp and dry. Now add the meat and bring to boil and simmer for about 5 minutes.
Take off fire and add lime juice and stir.