- Wash the Sabudana/sago under running water 2-3 times. Discard the excess water and leave it covered, to soak overnight. 
- In between if you feel the soaked sabudana looks dry then just add few splashes of water, keep it covered until you are ready with other ingredients. 
- Meanwhile coarsely crush roasted peanuts in mortar pestle or just pulse into mixer. No need to make a fine powder. 
- After that mash the boiled potatoes. Add  cumin, rock salt, sugar, minced green chillies, coriander leaves and lemon juice. To this add peanuts and soaked sabudana. 
- Mix everything together to make a dough. Pinch a lemon size dough and shape it round. Flatten it with your palms, smoothen the edges. 
- Don’t flatten them completely, keep them a little plump. This will make the vadas crisp from outside with a soft texture from inside. 
- Repeat the process, make all vadas and store in an airtight container. Place this in the fridge until you air fry them.