Fill a pot large enough to fit the artichokes with water. Rub the trimmed artichokes with lemon halves then squeeze lemons into the water. Add artichokes and bring to a boil.
Cook the artichokes until leaves are tender and you can just peel one away from base. Cold-shock the artichokes and drain upside down. Remove the center leaves and use a grapefruit spoon or a soup spoon to scrape out the choke from center.