|Plain flour||6 Ounce (About 175 Gram)|
|Butter||2 Ounce (About 50 Gram)|
|Mashed potato||4 Ounce (About 100 Gram)|
|Egg||1 , beaten|
Lightly grease two baking trays.
Sift the flour and salt into a bowl, then rub in the butter or margarine and lard until the mixture resembles fine breadcrumbs.
Work in the mashed potato to give a firm dough.
Knead the dough lightly, then wrap it in cling film and chill for 30 minutes, or longer if you have time.
Roll the dough out on a lightly floured board into a 20 cm/8 in square, then cut the sheet of dough into 16 5 cm/2 in squares.
Using a palette knife, carefully transfer the squares to the prepared baking trays and glaze them with the beaten egg.
Bake the potato crackers in a moderately hot oven (190C, 375F, gas 5) for about 20 minutes, or until golden brown.
Remove the hot biscuits from the trays and transfer them to a wire rack to cool completely.