Place as many peeled chopped potatoes as you feel you can eat into a roomy pan. Chop into similar sized chunks. The type of potato you use should be a a large main crop, variety, Maris piper or Maris barb are good, as are King Edwards and red Desire or Yukon Gold (an Amercian variety with a texture like butter being grown in Northumberland by Carrol’s Heritage Potatoes), the main thing to look for is type of potato that is not too young and will have the right texture when it is mashed, so any so called ‘new’ or salad potatoes will not do.
So back to the mash. Place your pot with potatoes covered in cold liberally seasoned water 2tbls spoons per 2 pints is good guide. Most of this salt will not be consumed remember it is there to season the potatoes which are large bland lumps of carbohydrate. Bring to rapid boil and turn down the heat to a gentle simmer for 10-15 minutes till cooked but not falling apart. Drain thoroughly and mash with a masher or put through a food mill (mouli de legume) if you have one. Now on a low heat and start by adding to a splash of warm milk and some salt (2-3tsp). I don’t put pepper in mash but that doesn’t stop you, beat that in with a wooden spoon, add cold unsalted butter in small pieces, beating well after each addition. For six 8oz of butter is a good idea, you can add less but it wont taste as good! This may sound a bit long winded but it does produce the best mash, and once you have done a few times it will not seem so arduous.