Rinse sabudana or tapioca pearls for 1-2 minutes or until water runs clears.
Soak the sabudana in 2 cups of water for 2-3 hours or until it is almost double in size. Depending upon the quality of the sabudana, soaking time may vary.
Using a fine mesh strainer, drain all the excess water from the sabudana. This is important, please do not skip this step. Excess water will make hard to shape the vada or patties.
Boil, peel and mash the potatoes to a smooth consistency.
Dry roast the peanuts on medium to low heat, until you see some charred spots on the peanuts.
Once completely cool, remove the husk and using a rolling pin, slightly crush the peanuts.
In the same pan, dry roast some cumin seeds, cool and slightly crush the seeds using mortar and pestle.
Chop green chili, ginger, cilantro.
In a mixing bowl, add soaked, and well drained sabudana or tapioca pearls. Add mashed potatoes, roasted and crushed peanuts, roasted and crushed cumin seeds, green chili, ginger, fresh chopped cilantro, some freshly squeezed lemon juice, pink salt and salt to taste. Mix everything to foam a semi-soft dough.