Marinate the fish pieces with salt, and set them aside for 10 minutes.
Heat oil in a wok.
Fry the chopped onions until they turn dark brown.
Take out the fried onions and place them on a plate. They will be used as beresta.
Take another pan and heat oil in it.
Fry the fish until golden brown, and then transfer them to a plate.
Add the whole spices such as bay leaf, cardamom, cloves, cinnamon and give them a good stir.
Add the ginger garlic onion paste and mix well.
Add some salt.
Add the cashew-raisin paste.
Add half of the beresta (fried onions) and stir well.
Reduce the flame to low. Add yogurt and mix well.
Add warm water according to desired gravy consistency.
Once the water comes to a boil, add the fried fish.
Sprinkle shahi garam masala.
Add ghee for a royal flavor.
Turn off the stove. Fish Korma is ready and sprinkle the remaining beresta (fried onions) over it. Serve it with steamed rice.