Soak the sabudana in water overnight or for 3-4 hours. Most of the water should be soaked when you are ready to cook. If there is any leftover water, drain it using a colander.
Heat a wok or kadhai on medium-high heat. Add oil, cumin seeds and green chili to it.
After they starts to splutter, add the potatoes and salt. The potatoes will take about 5 minutes to get cooked and lightly browned. You can cover with a lid for the initial 2-3 minutes to expedite the cooking.
Add the sabudana pearls and peanuts . Mix well.
Change to low-medium flame, keep the lip open and let it cook for about 3 minutes.
When the sabudana is cooked, the pearls should be transparent and not sticky. Mix the juice of one lemon and garnish with cilantro. Serve hot for breakfast or as a snack.
Notes
You can check if the sabudana is soaked well, by mashing it between your fingers. It should get easily mashed.
If you want to reduce the cooking time for the potatoes, you can soak the cubed potatoes in water and microwave for 2-3 minutes before adding.
You can roast peanuts on a pan or in the microwave. I usually roast in the microwave. Keeping them for 1 minute at a time for up to 2 minutes and 30 seconds intervals after that. It is good to keep monitoring the progress, so they don't get burnt.