Keep all the ingredients ready.
Take any fish for the recipe. Here we have taken yellowtail catfish (kosh or pangas).Clean the fish pieces and marinate with salt and turmeric powder for 10-15 minutes. In a pan heat oil. Fry fish pieces till golden brown. Drain and keep aside.
In the same oil, fry the potato pieces. Add little turmeric and salt. When golden brown, keep aside.
In the remaining oil add mashed garlic, ginger paste and onion. Fry till translucent. Add turmeric and salt. Stir and add fermented bamboo shoots and sliced green chillies. Fry for 5-10 minutes until the ingredients stick to the pan.
Add hot water and allow to boil. Pour water as per your desired quantity of gravy.
Now, add the fried potato pieces. Stir well to combine.Cover the pan and cook till potatoes are completely cooked.
Add fish pieces and cover the pan again. In medium heat cook for another 5 minutes.
Remove from heat.