For preparing the delicious dish, first cut raw mango into medium sized pieces. Keep it aside. Clean, wash and drain well the fish pieces.
Heat oil in a kadai, add fenugreek, dry red chillies, shallots, ginger, garlic, green chillies and curry leaves. Saute well until golden brown in color.
Add chilly powder, coriander powder, turmeric powder and saute well in a low flame.
Add 1 cup medium thick coconut milk and let it boil. Add mango pieces and cook.
Add sardine fish pieces to it, cover it with a lid and cook well. Let the gravy thicken a bit. Next, add thick coconut milk and put off the flame before boiling starts. Pour 1 tbsp coconut oil into the curry dish.
Serve the curry hot with rice. The tangy flavored spicy gravy makes a great dish.