Fold the top third down to the centre, then the bottom third up. Chill for 10 minutes. Remove from the fridge and with the folded edges to the sides roll the pastry out again in one direction to form a rectangle approximately 30 x 20cm. Keep edges straight and even. Fold as before, cover with cling film and chill for another 10 minutes. Repeat this process a further two times. After the last time chill the pastry for an hour.