Soak Bengal gram dal in water. Coarsely grind the dal. In a pan, heat ghee. Add curry leaves mustard seeds, and cumin seeds. Let them crackle. Then add the ground split Bengal gram dal and roast. Season with turmeric powder, sugar, lemon juice, and salt. Mix well. Transfer the mixture to a bowl, add grated raw mango and chopped coriander. Mix well. Transfer some mixture to a medium sized bowl and flatten the surface. Transfer some mixture in a small mould. In the serving plate, turn the bowl and mould upside down. Garnish with curry leaves and chopped coriander.