Trim the artichokes by snapping off tough outer leaves until you reach tender pale bases. Cut off at least 1 inch (2.5 cm) from the top. Rub cut surfaces with lemon, squeezing on juice to prevent discoloring.

From the center, cut away the small leaves with prickly tips and scrape out the fuzzy choke beneath them, without cutting away the tender bottom. Pare away any tough green parts left on the outside. Keep the stem attached.

Peel the stem by removing the tough green outer layer, leaving the white core intact. Rub all newly cut surfaces with lemon.

Mix parsley, garlic, mint, salt, and a few grindings of pepper. Reserve one-third. Press the rest into each artichoke cavity, rubbing it into the inner sides.

Stand artichokes in a heavy, lidded pot, tops down and stems up. Rub the outside with the reserved herb mixture. Add the olive oil plus enough water to cover one-third of the leaves, but not the stems. Cover the pot with doubled paper towels (or muslin) soaked in water, then set the lid on top, tucking any overhang back over the lid.

Cook over medium heat for 35 to 40 minutes, until a fork easily pierces the thick part between the stem and the heart. Transfer to a platter with stems up. Reserve the oil and juices, and pour them over only just before serving.