Put the potatoes in a large saucepan of cold water, bring to the boil and add some cooking salt. Cook on a continuous simmer for 18 to 20 minutes until the potatoes are tender.

Drain well in a colander and let them sit for a minute or 2 to steam dry.   Meanwhile, add the milk and butter to the saucepan and put on a low heat to warm the milk and melt the butter.   Turn off the heat and add the cooked potatoes.   Mash well until the potatoes are smooth and the milk and butter combined.   Season with salt, if needed and black pepper, to taste – stir again well to combine the seasoning.