Peel some Dutch potatoes, cut them into quarters and cook them quickly in boiling salted water. When cooked, drain and dry them out in the oven for a few minutes then pass them quickly through a sieve.
Replace in a pan and vigorously mix in 200g (7oz) butter per 1kg (2¼lb) purée; now add approximately 2½dl (9fl oz or 1⅛U.S. cups) boiling milk a little at a time until the right consistency is reached. Reheat but do not allow to overheat.