Step by step

Peel and prepare the artichokes, removing the stem, tough external leaves, and the tips. Add some lemon juice to a bowl of water.

Tips
When cleaning the artichokes, wear latex gloves or rub your hands with lemon juice. Just as artichokes not dipped in lemon water will tend to blacken, your hands will blacken too if you don’t take any precautions.
Trivia
Apparently, the botanist Castore Durante, who lived in the sixteenth century, used a concoction made from artichoke leaves to determine whether a woman was pregnant or not. If immediately after drinking the woman in question vomited, she was indeed pregnant.