Artichoke base. When artichokes have reached the stage where the leaves are too tough to eat, these are prepared by breaking off the stem of the artichoke by bending it until it comes off. Cut the base flat and then remove the leaves. Trim the outside of the heart and then remove the choke, being certain to remove all last traces. Rub the heart with lemon to prevent it from discolouring or put into acidulated water. These are sometimes referred to as artichoke hearts, which are from younger artichokes in which the bracts have not yet formed the choke and are included with the base. In the Rialto Market in Venice you will see artichoke sellers surrounded by heaps of leaves as they prepare these for use stewed, in a risotto, sautéed.