Heat oven to 425°F (220°C). Use a large knife to cut off the stem at its base and 1 1/2 to 2 in. (4 to 5 cm) off the top. Pull off the tough outermost leaves and yellow centre leaves and scrape out the inedible fuzzy centre pieces (the choke) with a spoon, leaving the heart intact (the solid, pale green base). Trim prickly tips with kitchen shears and rub edges with fresh lemon juice to prevent discolouration. Gently spread leaves apart to create space for stuffing.
In a large bowl, combine breadcrumbs, Parmesan, parsley, garlic, salt and pepper. Fill centre of each artichoke with breadcrumb mixture and work excess between leaves.
Transfer stuffed artichokes to a shallow baking dish. Drizzle with olive oil. Fill dish with 1 in. (2.5 cm) of boiling water. Cover dish with greased foil and seal edges tight. Bake until a sharp knife easily pierces through the top into the heart below, about 45 min. Remove foil and broil until tops of artichokes are golden brown, about 3 min. Spoon cooking liquid over each artichoke and serve warm.