Preheat oven to 200C Gas Mark 6. Grease a baking sheet. Rub the butter into the flour, then
stir in the salt, baking powder, sugar and mashed potato. Mix in enough egg and milk to make a
very soft dough. Knead lightly, then roll out to
12mm-1cm / 1/2-3/4 in thick. Using a glass, pastry cutter or knife,
cut out 8-10 scones. Place the scones on the baking sheet
and brush with egg or milk. Bake for 20-30 minutes.
