Marinate the fish with half tsp turmeric powder and salt.. Keep aside for 5 mins

Heat a pan add mustard oil then fry the marinated fish.. Keep aside

Take a big bowl with air tight lid

Now in that bowl add mustard paste, curd, cumin powder, Red chilli powder, turmeric powder, salt, sugar, green chilli, mustard oil and little water.. Mix them well

Now add the fried fish. Mix well.. Close the lid

How heat a big pan add water, now place that container into the water.. Cover the pan

Cook in a low flame for 20 mins

Now off the gas.. Remove the container from pan, And carefully open the lid of the container..

Rui Bhapa is ready.. Serve hot