The original recipe calls for fresh artichokes which allows you to cook them to tenderness but not overly soft. I used canned artichoke hearts to speed up the process and make it more affordable. If you are lucky enough to live where artichokes are plentiful, try it with them. (I will include the original directions for cooking them)
IF YOU ARE USING FRESH ARTICHOKES, FOLLOW THIS PROCESS THROUGH STEP 4. IF USING CANNED, START AT STEP 5 AND PROCEED.
Bring a large pot of water to a boil. Add the lemon juice and 2 tablespoons of salt.
Snap off the stems of the artichokes and reserve. Trim the artichokes of all but their innermost leaves. Cut about 2 inches off the top of each artichoke and discard. Add the artichokes to the boiling water. Peel the tough outer skin off the stems and add the stems to the water. Place a small bread plate or other weight on top of the artichokes to keep them submerged. Lower the heat to a slow boil and cook until the artichokes' bottoms are just tender when pierced with the tip of a small knife through the bottom, about 15 minutes. Drain and let cool.
Trim the rest of the leaves off the artichokes and scrape out the chokes – the fuzzy centers – with a spoon. Cut the bottoms into quarters and the stems into 1/4-inch rounds.
Heat the oven to 375 degrees F.
Wash the chard well and shake off any excess water, but do not dry. Strip the leaves away from the stems of the Swiss chard. Cut the stems into 1/2-inch pieces and the leaves into 1 to 2-inch pieces, keeping the stems and leaves separate.
Heat 2 tablespoons of the butter in a saute pan over medium-high heat. Add the chard stems and the onions and lower the heat to medium. Cook, stirring, until the onions are tender, about 5-7 minutes. Add the leaves and continue to cook until the stems and leaves are tender. Drain off or cook down any excess liquid from chard.
Add the artichokes, and 1 Tbsp butter if desired Season with salt and pepper. (Remember that the Parmesan cheese is salty, so go light and adjust seasonings after adding cream and cheese in next step)
Put the artichokes, onion and chard into a 1 1/2 to 2 quart gratin dish. Drizzle the cream and sprinkle the Parmesan over the vegetables. Adjust seasonings.
Bake until the cheese is melted and the cream is bubbling, about 15 minutes. While baking, melt remaining 1 Tbsp butter and mix well with the seasoned bread crumbs.
Raise the heat to 425 degrees F, sprinkle on the bread crumbs and bake until crumbs are browned and the inside of the gratin is hot, another 7 to 10 minutes. Serve immediately.