Mash the sweet potato and garlic with the milk until smooth.
In a medium frypan, toast the macadamias until lightly browned, remove from the pan immediately and set aside.
Just before serving, heat the ghee, macadamias and honey over high heat until it just starts to darken in colour. Be VERY CAREFUL as it will foam up and increase in volume!
Immediately remove from the heat and pour over the mashed sweet potato.