Cook the potaotes and lower them whole in their skins into a pan of salted boiling water, bring back to the boil and simmer for 10-15 minutes until just soft. Test with a sharp knife – you should have to push the knife in, it should not slide in easily, otherwise the potatoes will be overcooked and mushy and will have absorbed too much water. Peel them quickly, as the cooler they get, the less fluffy they become. Hold them in a tea towel to peel as they are hot.