Peel and chop the potatoes into large chunks. Place in a large pot of salted water and boil until fork tender.
Drain and allow to steam dry for a few minutes.
Combine the cream, milk, garlic, salt and pepper in a small saucepan and heat until the butter is melted.
At this stage, you can mash your potatoes with a traditional potato masher, whip them with a mixer or put them through a ricer. It really depends on the finished texture you are after. We love them any way. When I don't have a lot of time I use a traditional masher. This will give you mash containing a few small lumps. A ricer will give you the silkiest, smoothest result.
Stir the warmed cream mixture into the mashed potatoes then add the parmesan cheese and season to taste before serving.