Boil the potatoes, peel and cut into bite size pieces Slice the onion. Place the potato in a bowl and and add the salt, turmeric, chilli powder and paprika powder Heat the oil and when hot add the curry leaves followed by the onion, mustard and cinnamon stick Fry until the onions are a golden brown, then add the potato and keep tossing with the onion until browned and heated through. Discard the cinnamon stick and sprinkle the lime juice on top just prior to serving. From "A taste of Sri Lanka" by Indra Jayasekera, Isbn #962 224 010 0