Marinate the prawns with little turmeric powder and salt for atleast 1 hour.

Make a fine paste of the onion in a grinder.

Mix the poppy seeds and mustard seeds together and soak for atleast 1/2 an hour.

Now, make a fine paste of poppy-mustard seeds adding the green chillies.

Heat oil in a pan and shallow fry the diced potato adding little turmeric powder and salt. Once the potato pieces are little soft, remove from the oil and keep aside.

Heat oil again and shallow fry the prawns. Once the prawns turn golden, remove from the heat and keep aside.

Again, heat oil in the same pan and add red dry chillies and fenugreek seeds, saute for 30 seconds.

Now, add onion paste and ginger-garlic paste. Saute till the paste becomes little concentrated.

Add the chopped tomato, cumin powder, turmeric powder and salt. Keep stirring until the tomato blends.

Now, pour the poppy-mustard gravy and stir well.

Add 1 cup of warm water, mix well and cover the lid. Lower the flame and bring it to a boil.

Open the lid and slowly add the prawns and potato, mix well with the gravy. Check the salt (if less, add some more) and cover the lid again.

Lower the flame and cook it for 10-15 minutes or until the prawns get cooked well.

Turn off the flame and your Chingri Posto is ready to be served now. Remove it in a serving vessel.