Step 1

To make the filling: Preheat the oven to 350 degrees.

Step 2

Pierce the potato several times with a fork. Bake it directly on an oven rack for 1 hour, or until tender. Refrigerate until cool enough to handle.

Step 3

Meanwhile, pull off the outer leaves of the artichoke, then pull out or cut away the pale green leaves in the center. Trim the stem to 1 to 2 inches. With a paring knife, trim away the dark green outer portion of the heart and the stem. Split the heart in half and use a spoon or small paring knife to carve out the prickly choke at its center. Cut the artichoke into 1/8-inch-thick slices. Set aside.

Step 4

When the potato is cool enough to handle, peel it, quarter lengthwise, and cut crosswise into 1/8-inch-thick slices; it’s OK if it crumbles. Set aside.

Step 5

Warm the oil in a large skillet over medium heat until it is shimmering but not smoking. Add the onion, artichoke, and salt, reduce the heat to medium-low, and cook, stirring every few minutes, for 10 minutes, or until the vegetables are tender. Add the asparagus and Swiss chard and stir until the chard starts to wilt. After 2 to 3 minutes, increase the heat to medium-high and cook until the chard is tender and any water has evaporated, about 1 minute more. Set aside to cool slightly.

Step 6

To make the frittata: Preheat the oven to 325 degrees.

Step 7

Beat the eggs and yolks together in a large bowl. Stir in the cream, the Gruyère, 3 tablespoons of the Parmigiano, the herbs, bread crumbs, potato slices, asparagus-chard mixture, salt, and pepper to taste.

Step 8

Heat the 1 tablespoon oil in a 10-inch ovenproof nonstick skillet over medium-high heat. Add the egg mixture and, with a rubber spatula or wooden spoon, stir to scramble the frittata for 30 seconds, scraping the bottom of the pan and breaking up any large egg curds. The frittata will still be mostly wet, with evenly dispersed cooked egg throughout. Remove the pan from the heat, smooth the top of the frittata, and gently tap the pan on the counter to settle it.

Step 9

Slide the pan into the oven and bake for 20 to 30 minutes, or until the frittata is firm to the touch. Remove from the oven and turn out onto a large platter (or cut it into wedges in the pan using a nonabrasive spatula). Garnish with the remaining 1 tablespoon Parmigiano and a drizzle of olive oil. Serve hot, warm, or at room temperature.