1 pound chilled salted butter, cut into large pieces
5 large eggs, beaten
For the filling
12 ounces prosciutto, in 1/4-inch dice
8 ounces boiled ham, in 1/4-inch dice
8 ounces pepperoni, in 1/4-inch dice
8 ounces soppressata, in 1/4-inch dice
8 ounces mozzarella, in 1/4-inch dice
8 ounces provolone, in 1/4-inch dice
2 pounds ricotta
4 ounces grated pecorino Romano
10 large eggs, beaten
1 teaspoon pepper
1 large egg, beaten, for brushing crust.
For the dough
In a large bowl, whisk together 6 cups flour and the salt. Using a pastry cutter, large fork, or two knives, cut the butter into the flour until the mixture resembles coarse crumbs. Add eggs and knead for 1 minute. Add about 1 1/4 cups ice water, a little at a time, to form a cohesive dough. Knead the dough on a lightly floured surface until it forms a large smooth ball, about 5 minutes. Cover with plastic wrap and set aside for 30 minutes.
For the filling: Mix the meats, cheeses, the 10 eggs and pepper in a large bowl.
Heat oven to 350 degrees. Divide the dough into two pieces: two-thirds for the bottom crust and one-third for the top. On a lightly floured surface, roll out the larger portion of the dough into a rectangle to line the bottom and sides of a 10-by-15-inch glass baking dish, with some overhang. Add the filling and smooth it lightly. Moisten the edges of the dough with a little water.
Roll out the remaining dough to cover the top of the dish with some overhang. Trim off excess dough and crimp the edges to seal. Poke several sets of holes across the top with a fork. Bake for 45 minutes. Remove from the oven and brush top and edges with the beaten egg, then return to the oven until golden brown, another 45 minutes. Let pie cool completely before serving.