Grind together, the bari elaichi, laung and daalchini. Put aside until further use. Boil potatoes until half cooked. Peel while still warm. Pierce each potato 2-3 time with thin wooden toothpick. Heat oil in a kadhai, fry potatoes on medium heat until floating on top and golden brown in color. Drain excess oil and keep aside. To the dahi, add salt, besan and 1 cup water. Whisk well, until smooth and lump-free. Reheat 4tbsp of the same oil in another pan. Add red chillies and chhoti elaichi and fry for a minute. Remove from flame, allow to cool slightly and then pour into the dahi, stirred continuously. Return to flame and bring to a boil, again stirring continuously. Add potatoes along with soonth, saunf and ground masala. Cook over medium heat for 5-10 minutes or until the curry thickens. Serve hot accompanied by Boiled rice.