Step 1

In a bowl, or in a food processor fitted with a steel blade, mix together the flour, sugar, salt, and zest. Pulse or use a fork or pastry blender to work in the butter until the mixture resembles coarse crumbs.

Step 3

Whisk 3 of the egg yolks together in a bowl with the water. Add the yolk mixture to the flour mixture and process in the food processor or mix with your hands until a soft ball of dough is formed. If the dough seems dry, add a little water. Gather the dough into a ball. Divide it in half and wrap each in plastic wrap. Refrigerate overnight.

Step 4

Drain the porcini and dice them. Melt the butter in a medium size sauté pan, stir in the onions and cook just until the onions soften. Add the mushrooms and fresh peas and cook 1 or 2 minutes. Transfer the mixture to a large bowl and set aside. Return the saute pan to the stovetop.

Step 5

Mince the celery, carrot, parsley, and onion together with a chef's knife. Melt the butter in the same saute pan used to cook the mushrooms. Stir in the celery mixture and cook over medium heat until it softens. Stir in the pork, livers, salt and pepper and cook, stirring often, until the pork and livers turn gray. Transfer the ragu to the bowl with the mushrooms. Stir in the besciamella sauce. Add the cooked penne rigate and toss the mixture well. Set aside.

Step 6

Preheat the oven to 375F. Butter a 10 x 3-inch spring form pan.

Step 8

On a lightly floured surface roll out each half of pastry dough into a 16-inch diameter. Fit one half of the dough in the pan, bringing it up the sides and letting the excess hang over the edge of the pan.

Step 9

Spread the filling in the pan, sprinkle the cheese over the top, and cover with the second sheet of dough. Seal the edges. Use any pastry scraps to make decorations for the top.

Step 10

Brush the top with the remaining egg yolk; cut a small x in the center of the top for venting, and bake for 40-50 minutes or until the crust is nicely browned. Cool for 30 minutes before releasing sides.

Step 11

Cut into wedges to serve.