Roast the spices: pepper corns, cinnamon, cloves and poppy seeds. Grind into a powder and keep aside.
Take a frying pan and pour oil. Heat the oil and fry chopped onions.
Add the ginger and garlic pastes and saute in low heat for some time.
Add the previously prepared spice powder, turmeric, cummin, nutmeg, chilly powder, coriander powder, coconut, vinegar and required salt. Saute for sometime till oil accumulates on top.
Add two cups water to the above mixture and stir well. Bring to boil.
Lower the flame and add the fish pieces one by one. Cover with a lid and cook till the fish pieces are done.
Remove from fire and garnish with chopped coriander leaves.
Goan fish xacuti is ready and serve hot.