Rub the fish with turmeric and salt. Let sit for 30 minutes.
Heat oil in a large frying pan. Add panch phoron and fry till fragrant, about 30 seconds. Add the green chillies and ginger. Add the fish and fry till browned, about 2 minutes. Remove the fish and keep aside.
Mix the curd with ½ cup water, sugar, and salt. Add the curd to the frying pan. Bring to a boil and reduce flame to simmer. Add the fish and cook till the fish is done, about 5 minutes. Garnish with coriander leaves and serve with plain rice.