Like apples and potatoes, artichokes will oxidize (discolor) if left out in the open. Be sure to submerge them as soon as you're done trimming. This article was written by the Healthline Editorial Team: http://www.healthline.com/health-recipes/braised-artichokes —Healthline
Remove zest from lemons with a vegetable peeler and set aside.
Fill a large bowl halfway with cold water and squeeze one of the lemons into the water. Remove tough outer leaves of an artichoke until you get to the pale green inner leaves. Trim the dark green portions from the stem and base and then trim the bottom of the stem. Cut 1 inch off the top of the artichoke and then cut in half before placing in the water. Repeat with remaining artichokes.
When ready to cook, drain artichokes and place in a large saucepan. Squeeze the remaining lemon into the saucepan and add lemon zest, garlic, rosemary, salt, and olive oil. Add just enough water to cover artichokes. Place a piece of parchment paper the diameter of the pan on top of the artichokes. Weight the parchment with a heatproof plate that rests directly on the artichokes. Bring to a boil over medium-high heat, then reduce the heat to medium and simmer for 5 minutes.
Remove from heat and let the artichokes cool in the pan until tender when pierced with a knife, about 1 hour. Sprinkle parsley on the top and serve immediately.