Drain sabudana completely to remove any excess water. Add the soaked sabudana to a bowl. Add the potato, peanut, ginger, green chilies, cumin seeds, coriander leaves, salt to taste, and lemon juice, and mix well. Add flour if needed and mix well. This will help bind and prevent the vada from breaking while frying.
1 Potato, ¼ cup Peanuts or Cashewnuts, 1 inch Ginger, 2 to 3 Green chilies, 1 tsp Cumin seeds, 1 to 2 tbsp Coriander leaves, ½ tsp Salt to taste, 2 tbsp Flour, 2 tsp Lemon juice