Soak tandulu in water for 4 hours.
Soak fenugreek seeds for 1 hour.
Soak poha/aval for 5 mins.
Grind soaked poha, fenugreek seeds and crushed jaggery together to a fine paste. Do not add too much water since the batter has to be thick.
Add turmeric, watermelon pieces, yogurt, grated coconut and tandulu.
Grind all ingredients and make a thick batter.
Add a pinch of salt.
Keep aside the batter in a vessel overnight.
In the morning, put a thavo(polachi kayali) on the stove and put 1/2 tbsp oil and spread.
Add 1 davalo of batter on the hot thavo and spread it in the shape of a circle. (the circle should be thick and not like pan polo).
Roast under cover ONLY ONE SIDE. The end product is called soornali(surnali).
When the soornali becomes brownish, remove it from thavo.