Neapolitan Potato Pie

Difficutly: easy
Time: 2 Hours
Portion: 8 servings
Ingredients:
2 1/2 lbs yellow-fleshed potatoes such as Yukon Gold (3 or 4 large), scrubbed1 cup Milk1/2 stick (1/4 cup) unsalted butter, softened, plus additional for buttering pan1/4 cup fine dry bread crumbs1/2 teaspoon salt1/4 teaspoon black pepper1/2 teaspoon freshly grated nutmeg1 large egg, lightly beaten1/2 lb mozzarella (preferably fresh) chopped1/4 lb salami or prosciutto, chopped2 1/2 oz finely grated Parmigiano-Reggiano (1 cup plus 2 tablespoons)
Directions:
Cover potatoes with salted cold water by 2 inches in a 5-quart pot.  Bring to a boil, then reduce heat and simmer, uncovered, until potatoes are tender, 18 to 20 minutes.  Shortly before potatoes are done, bring milk to a simmer in a small sauce pan over moderate heat, then remove from heat. Put oven rack in middle position and preheat oven  to 400 F.  Butter a 2 – to – 2 1/2 quart shallow baking dish and sprinkle with bread crumbs.  Drain potatoes well in a colander.  When cool enough to handle, peel potatoes and return to pot along with hot milk, salt, pepper, nutmeg and 3 tablespoons butter.  Mash with a potato masher until combined well and almost smooth.  Stir in egg, mozzarella, salami (or prosciutto) and 1 cup Parmigiano-Reggiano.  Spread potato mixture evenly in baking dish.  Sprinkle with remaining 2 tablespoons Parmigiano-Reggiano and dot with remaining tablespoon of butter. Bake until top is browned, 35 – 45 mintues. Let potato pie stand 5 mintues before serving.