Blend half of the lime juice with turmeric and rub inside the fish.
Blend prawns, chillies, ginger, mint, coriander, and salt until combined.
Add remaining lime juice to the prawn mixture and stuff each fish.
Press the fish flat and chill in the refrigerator.
Heat oil in a saucepan and cook the cinnamon stick for 30 seconds.
Sauté onions until soft and brown.
Mix chilli, cumin, and coriander powders with vinegar and water into a paste.
Add ginger, garlic, and chillies to the onions and sauté for 3 minutes.
Stir in the spice paste, followed by tomatoes, tamarind, and jaggery.
Cook gently for 5 minutes, season, add coriander, and remove from heat.
Preheat the oven to 160°C.
Sear the sea bass in a hot oven-proof frying pan until browned on both sides.
Transfer the pan to the oven and roast for 12 minutes until cooked.
Serve fish topped with patia sauce and fresh coriander.