In a pan, heat up a little oil/ghee, and add in the cumin seeds, and wait till it crackles, before adding chopped/slit green chillies and curry leaves.
In a couple of minutes, when the curry leaves start getting lightly roasted, add in the whole peanuts, and roast them for 3-5 minutes, till they get well roasted.
Then add in the chopped / diced boiled potatoes, and a little bit of salt (to season at every stage), and saute them for 2-3 minutes.
Next add in the sabudana that is mixed with the peanut powder, sugar / jaggery powder, the rest of the salt, and lemon juice, and give everything a quick mix.
Cook covered on medium low flame for 3-5 minutes till the sabudana is translucent. DO NOT over-cook or over-stir.
Garnish with chopped coriander leaves, and serve HOT.