Clean the fish and cut into one-inch pieces. Cut the tomatoes into medium size pieces. Chop the ginger Crush the red chilli with garlic, pepper and ginger and keep aside. Chop the onions finely. Cut the green chillies lengthwise. Put the oil in a cooking pan and sauté the onion and green chillies for five minutes.
Add the crushed chillies, pepper, garlic and ginger. Fry for three minutes until the smell of chilli comes out. Dissolve the coconut milk powder in a cup of water. Add turmeric powder and let it boil. Add the fish and salt. Cook well and add the tomato pieces.
Cook for five minutes on a low flame. Add the lemon juice and curry leaves.