Rinse the sabudana pearls under running water two to three times until the water runs clear, then drain thoroughly.

Add just enough water to barely cover the rinsed sabudana, cover the bowl, and let it soak until each pearl turns soft and translucent.

Boil the potatoes until fork-tender, then peel and mash them smooth with no lumps remaining.

Dry roast the peanuts in a pan until fragrant and lightly browned, then coarsely crush them with a mortar and pestle or rolling pin.

In a large bowl, combine the soaked sabudana, mashed potato, crushed peanuts, green chilies, ginger, coriander leaves, cumin seeds, sugar, lemon juice, and salt, mixing until it holds together as a cohesive dough.

Cover the mixed dough and let it rest so the flavors combine and the sabudana firms up slightly, making it easier to shape.

Divide the rested mixture into equal portions and flatten each one between your palms into a round, slightly thick patty.

Heat the oil in a kadai over medium heat until a small piece of the mixture dropped in sizzles and rises steadily to the surface.

Slide the shaped patties into the hot oil in batches and fry, turning occasionally, until golden brown and crisp on both sides.

Lift the fried vadas onto a wire rack or paper towels and let them drain briefly so the crust stays crisp before serving.