Boil the potatoes in large pan of salted
water, with the lid on, for 15-20 mins until
tender. Drain well, return to the pan,
cover and leave to steam-dry for 1-2 mins.
Remove from the heat and mash the
potatoes until smooth. Push to one side
of the pan, add the butter and buttermilk,
then gently heat until the butter has
melted. Beat in the potato a little at a
time until smooth. Add the chopped
herbs and season with ground white
pepper and salt.