Carciofi con Patate In Umido

• 6 globe artichokes or 12 Jerusalem artichokes
• juice of 1 lemon

Peel off the outer leaves if using globe artichokes and trim round the base with a knife. Remove all spines that cover the base beneath the soft inner leaves and cut into 4. Drop into a basin of cold water mixed with the lemon juice. Alternatively, peel Jerusalem artichokes, cutting them into chunks of roughly the same size, and drop them into water with lemon juice.

Heat the oil in a l