Squeeze the juice of a lemon into a large bowl of cold water. Clean the artichokes, trimming away the tough outer leaves and leaving the ones that you will eventually eat. Cut away the top third of the artichoke and scrape out the choke, if there is one, with a teaspoon.
Leave about 2 cm (¾ in) of the stem, trimming the hard outer dark green part away down to a fine point. Leave the art