Soak the sabudana: Wash the sabudana and soak it in just enough water for 4–6 hours, or until soft. Drain any excess water.
Prepare the peanuts: Roast the peanuts, remove their skins, and crush them coarsely.
Cook the potatoes: Heat ghee or oil in a pan. Add chopped potatoes and cook until tender.
Add the ingredients: Add green chillies, soaked sabudana, crushed peanuts, and salt. Mix gently.
Cook the khichdi: Cook on low heat for 4–6 minutes, stirring occasionally, until the sabudana pearls turn translucent.
Serve: Add lemon juice, mix well, and serve hot.