Add the cardamom powder and pistachio and almond slivers, and mix. Remove from the heat and set aside to cool.
Add the powdered sugar and mix well.
Grease a six-by-eight-inch aluminium straight-sided shallow tray with the ghee. Pour the gram flour mixture into the tray and spread it evenly with a greased spatula.
Cool and cut into squares or diamonds and serve. Store the burfi in an airtight container.