4 large baking potatoes, scrubbed and
1 stick unsalted butter, softened
3 eggs slightly beaten
1/2 cup milk
1/2 cup grated Parmigiano Reggiano cheese
1/4 cup grated Pecorino cheese
1/4 pound diced ham
3 tablespoons minced parsley
3 ounces Provolone cheese, diced
1/2 pound mozzarella cheese (fior di latte) sliced

Butter a 9 x 12 inch baking dish and set aside.

Preheat the oven to 350F

Bake the potatoes in their skins in the microwave according to manufacturers directions. Cool and peel.

Mash the potatoes in a large bowl until smooth. Stir in the butter, eggs, milk, Parmigiano Reggiano and Pecorino cheeses. Stir in the ham and parsley.

Spread half the mixture in a 9 x 12-inch baking pan. Over lap the slices of provolone and mozzarella cheese on top of the mixture. Cover with the remaining mashed potato mixture.
Sprinkle the bread crumbs over the top. Drizzle the butter over the bread crumbs and bake the pie for about 20 minutes or until the top is nicely browned. Serve hot.

Variation: use thin slices of plum tomatoes instead of breadcrumbs for the topping.