Heat oven to 375 degrees.
Bring 6 cups of water to a boil and add 1 teaspoon salt and the greens. Stir to submerge. Boil, uncovered, for 12-15 minutes, stirring once or twice to ensure even cooking. Drain in colander, pressing on greens with the back of a spoon to remove excess water. When cool enough to handle, remove greens to a cutting board, mass them together and cut more finely.
While greens are cooking, draining and cooling, beat eggs and cream on low speed in bowl of electric mixer. Add prosciutto or pancetta, mozzarella and Parmesan, mixing well to combine.
Drain artichoke hearts in colander. Squeeze lightly with hand to remove excess water. Chop artichokes and add to egg mixture in bowl. Add drained, chopped greens and mix well. Spoon mixture into prepared pie shell.
Bake for 45-50 minutes.
Serves 16 as an appetizer. (If served as a main course, will serve 8.) May be frozen after baking.
Ingredient notes: Water-packed artichoke hearts come in either a frozen 8-ounce package (thaw and drain before using), or in a can that weighs 13 3/4 ounces net weight (8 1/2 ounces drained weight). We recommend prepared Pillsbury pie crusts sold in a red box in the refrigerated section of the grocery store near the butter. They are rolled out flat, and then folded in quarters, and have the best flavor of all the bought crusts, we believe. The Italian cured meat gives this a very elegant taste. You may also substitute sliced salami if that is more convenient for you, or even crumbled bacon.
Serving notes: Serve with melon slices and cherry tomatoes with a light dressing. May also be served as part of an antipasto platter.