Clean, wash and slice fish. Apply salt and keep aside.
Grind all the spices, garlic and ginger in the vinegar then add the sugar.
Heat oil on medium flame and sauté onion till golden brown. Add the ground spices to this and stir fry for 1 minute. Add the curry leaves and the water gradually. Stir cook 15 minutes till the sauce is thick. Add the fish pieces and cook for 8-10 minutes. Remove and serve.
