Place the potatoes into a large saucepan of cold salted water and bring to a boil, cook for 15 minutes or until tender, drain well, then return the lid to the pan and allow the potatoes to steam for 5 minutes.

Heat milk and butter in a small pan, then pour over the potatoes and mash. Sprinkle in grated cheese and beat with a wooden spoon until smooth. Season with salt and pepper.