The prickly pears should be perfectly ripe. It is essential to wear gloves when you peel them to avoid contact with the small prickles dotted about on the skin. Cut off both ends with a vegetable knife, and make an incision from top to bottom so that you can peel off the skin easily. Cut 4 of the fruits into slices 2cm (¾in) thick and put them aside in a bowl, sprinkled