1. Wash the fish well and lightly fry in a little oil till the pieces become firm.
2. Heat oil in a pan and add the onions and fry till light brown.
3. Add the ginger garlic paste and saute for a while.
4. Add the chilly powder, cumin powder, pepper powder, tomato puree and salt and fry for some time.
5. Add the fish and the vinegar and mix well.
6. Add a little more water and cook till the gravy is slightly thick. (Slices of Shark fish can also be used in this recipe to make Shark Fish Vindaloo.
7. However the pieces need not be fried before hand since shark meat is already firm)

Recipe courtesy: Anglo-Indian Recipes