Heat oil in a pan or kadai over medium heat. Add mustard seeds and fennel seeds and let them splutter.

Add finely chopped onion, green chillies, and curry leaves to the pan. saute until the onions turn golden brown.

Add ginger-garlic paste and saute for a minute until the raw aroma disappears.

Add turmeric powder, red chilli powder, coriander powder, cumin powder, and fenugreek seeds. Mix well and cook for a minute to release the flavours.

Add chopped tomatoes and cook until they turn soft and mushy. Pour in the coconut milk, stirring gently to combine all the ingredients. Season with salt and let the gravy simmer for about 10 minutes to allow the flavours to meld together.

Gently place the fish pieces into the gravy, ensuring they are submerged. Cover the pan and cook for 8-10 minutes or until the fish is cooked through and flakes easily.

Garnish the Chettinad Surmai Curry with fresh coriander leaves.

Serve the flavourful curry hot with steamed rice or roti.

Chettinad cuisine is known for its robust flavours and spice levels. Adjust the amount of red chilli powder according to your preference. The use of coconut milk adds a creamy and mellow balance to the spicy curry. Enjoy the delectable Chettinad Surmai Curry that showcases the unique culinary heritage of South India!