Cut into fish into small cubes. Marinate them with yogurt and garlic paste for 15-20 minutes. Heat ghee in a non stick pan.
Add salt, black peppercorns and the marinated fish pieces without the marinade. Saute till the fish gets almost cooked.
Add ginger paste and tomato puree and mix well. Add coconut milk and mix lightly.Add a pinch of turmeric powder to cashewnut paste and mix. Add this to the fish gravy.
Remove the pan from heat, add the remaining fish marinade, mix and keep it covered for 2-3 minutes. Add fresh cream and mix well. Garnish with coriander leaves and cashewnuts and serve hot.