Clean the fish and make slits on it as shown in the figure.
Take a bowl and add grated coconut, fennel seeds, coriander powder, chilly powder, turmeric powder, garlic, ginger and salt as required.
Combine well.
Add this mixture into a mixer grinder along with green chillies and little water.
Grind to make a semi coarse paste.
Add the ground paste and some curry leaves into the cleaned fish. Add lemon juice.
Marinate the fish with this and keep aside for just 10 minutes.
Heat a pan with oil. To get a kerala taste use coconut oil. When the oil becomes just hot enough, place the fish in the oil and fry on a medium flame.
After 3-4 minutes, turn it to the other side and add curry leaves. Fry until the fish is cooked through.
Serve hot along with rice, chappathi etc...