Soak the rice for 1 hr. Grind it for few seconds and then add mango pieces and grated coconut to the rice and grind it again into fine paste. Take a pan. Put 1 cup water and jaggery and heat it until it becomes thick syrup. Then to that syrup add the grinded paste. Heat it and while heating add ghee until the mixture leaves the sides of the pan and comes together. Then to that mixture add cardamom powder and cashewnut pieces. Grease a plate with ghee and pour the mixture into it. While the mixture is hot, mark it into pieces and when it cools down cut the marked pieces and serve it.