Cook again on medium high, stirring continuously until the moisture is almost gone; add more ghee if you want a richer halwa.
Once most of the moisture is gone and you get a thick mixture with ghee glistening from the edges of the halwa, stir in cardamom powder and give it a good stir. Remove from heat.
In a small saucepan, heat rest of the ghee and add cashew nuts; fry until light golden brown. Tip this into the halwa and mix well.