Discard the hard peel of Elephant Foot Yam and cut into cubes, wash well. 

Now transfer the oal pieces to a cooker, add enough water to submerge the pieces. Take off the flame after one whistle, open the lid after the steam dissipates, drain and keep aside.

Mix in ½ tsp of salt and ¼ tsp of turmeric powder to the freshly washed prawns, keep aside.

Heat ¼ cup oil in a kadai/deep frying pan over medium heat. Add the prawns and sauté until golden (for 2 minutes)in colour, remove and keep aside.

If there is not enough oil in the kadai add 2-3 tbsp more oil at this stage. We would be needing 4 tbsp oil to cook this dish.

Add the cubed potatoes and sauté over medium heat until golden brown, remove and keep aside.  

In the rest of the oil temper with the ingredients mentioned for tempering. Next to add cumin powder, coriander powder, red chilli powder, turmeric powder, salt, green chillies, and ginger paste. Mix and cook over medium heat for a few seconds. Now add a few tablespoons of water, keep stirring the masala until it starts leaving oil. Adding water at this stage prevents the spices from burning, helps to dissolve the masala, and enhances the flavour. 

Now add the boiled oal pieces and potatoes. Mix well and cook for 5 minutes over medium heat, keep stirring in between. Add ¾ cup of water, mix well and cook until the potatoes are done. If the curry is thickening too much, adjust by adding some water. This curry needs to be cooked with a moderate gravy, but don’t make it too thick because it tends to get a thicker consistency as it cools. 

Add fried prawns, sugar, and garam masala powder at the end of the cooking. Mix gently and cook for 2-3 minutes more. Transfer to a bowl, serve hot as a side with dal and steamed rice. It tastes great with plain rice sans dal as well.