Clean, wash and add the dal to boiling water. Add turmeric, salt, 1/2 of the finely chopped ginger, garlic and cook on medium heat for 2-3 hours or pressure cook for 1/2 hour. Uncover, cook further in small pan on low heat for 1/2 hour, stir and mash every now and then until a creamy consistency is achieved. Heat the ghee and add remaining ginger, stir add sliced onions, chilli and fry until golden brown. Add cumin or coriander(optional). Pour over dal just before serving.