Add enough vinegar and blend onion mixture to a thick paste.
Marinate the dried beef cubes in this paste and keep aside for 2 hours.
Heat ghee in a hard bottomed pan and fry sliced onion till dark brown in color. kepp aside. Fry beef pieces in the same oil till all the water evaporates and it becomes golden brown.
Now add the hot water, stir and cook covered in low flame till the beef is done. Add fried onion and curry leaves. Make it a dry masala.
Beef vindaloo, an apt dish with chappathis/roti is ready. Serve hot and enjoy.