At first, take a mixer grinder and add small sized chopped onion, ginger, garlic and water to make a smooth paste.

Then heat mustard oil in a pan.

Spread turmeric powder and salt as required on one chopped potato and pieces fish. Mix well.

Now add chopped potato and fry till it becomes golden in colour and then remove besides.

Add fish. Fry both sides well then remove besides.

Now add cumin seeds on same oil.

Add sugar in it. When sugar melts then add chopped onion and fry them.

Now add tomato sauce.

Add prepared paste of mixer grinder and saute till oil generates.

Now add remaining turmeric powder, coriander powder, cumin powder, red chilli powder and salt as per taste.

Saute again.

Now add fried potatoes and mix well.

Add water as required and cover it with lid for 2 minutes.

After 2 minutes, open the lid and add fried fish.

Again cover with lid and cook until potatoes becomes soft.

After that, open lid and add chopped coriander leaves and garam masala powder to this.

Mix well. Switch off the gas. Cover with lid and keep for 5 minutes.

Serve potato fish curry.