Marinate fish pieces with turmeric, salt, and lime juice. Set aside for 10 minutes.
Heat oil in a heavy-bottomed pan over medium heat. Add curry leaves and cinnamon stick, frying until fragrant.
Add sliced onion, green chilies, and minced garlic. Sauté until onion becomes translucent.
Stir in minced ginger, turmeric powder, and chilli powder. Cook for 1-2 minutes until spices are fragrant.
Add coconut milk and tamarind paste, stirring well to combine. Bring to a gentle simmer.
Carefully add marinated fish pieces and pandan leaf to the curry. Season with salt and pepper.
Simmer gently for 8-10 minutes until fish is cooked through and flakes easily. Avoid stirring too vigorously to prevent fish from breaking.
Taste and adjust seasoning as needed. Remove from heat and let rest for 2 minutes before serving.