Clean the fish and put some suits on it like shown in the figure.
Marinate the sardines with the ingredients under marination given in the recipe.
Rest it for about 1 hour.
Take all the remaining ingredients and keep it ready for preparing the gravy.
Heat oil a pan and splutter mustard seeds and add chopped ginger and garlic. Saute for few seconds.
Then add chopped shallots and curry leaves. Saute for few minutes.
Add chopped tomato and 2 tbsp hot water. Mash the tomato well. Now add all powder ingredients- kashmiri chilly powder, turmeric powder and pepper powder and saute for 30 seconds.
Combine well, cover with a banana leaf(optional) and cook for 2 minutes in low flame.
Place the marinated Sardine on top of the masala and cook for 4-5 minutes on low to medium flame.
Flip and cook the other side. Add curry leaves and pour the coconut milk on top. Keep in low flame for a few more minutes.