Make the Dough-

1. In a large bowl, combine the flours and salt. Make a well in the center, and add the butter and olive oil. Using pastry cutter, or two butter knives, or your fingers, blend in the fats until the mixture forms coarse crumbs. Sprinkle 7 tablespoons of the cold water over the mixture and blend together until the dough begins to form. Add more water in small additions as needed. Form dough into a ball and wrap in plastic wrap. Chill for 30 minutes.

Make the Filling-

1. In a small bowl, combine 1/4 cup of the pancetta, about 1/2 teaspoon of the garlic, 1/4 cup of the shallots, and a generous amount of black pepper. Set aside.
2. In a medium skillet, saute mushrooms until cooked through and lightly browned. Set aside.
3. Cook the remaining pancetta in the olive oil in a large skillet over medium-low heat until it the fat has rendered, about 5 minutes. Add remaining shallots and cook, covered, for about 15 minutes or until the shallots have softened. Uncover skillet, raise heat to high and cook until filling has browned, about 5 more minutes. Add the spinach, reduce heat to medium, and cook until spinach is tender, about 7 minutes.
4. Stir in remaining garlic and cook for about 30 seconds to a minute, until the garlic is fragrant. Place the filling into a large bowl and let cool.
5. Stir the mushrooms to the filling mixture, then add 1 1/2 cups of the Parmigiano-reggianoand the reserved pancetta/shallot/garlic mixture. Adjust seasonings as needed, and add more Parmigiano if you desire. Blend in the eggs.
6. Preheat oven to 400 degrees F with a baking stone set on the rack in the lowest position.
7. Divide dough in half. On a lightly floured surface, roll each half of the dough into a 14-inch circle.
8. Sprinkle a pizza peel or wooden board with a little bit of flour or cornmeal to prevent sticking. Place one circle of dough on the board and top with the filling mixture, leaving a 2 inch border around the edges.
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10. Dampen the edges of the bottom crust with water, then top with the second circle of dough,and pinch the edges together. Fold the edges over and crimp. Cut a few slit in the top of the crust to allow the steam to escape.
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12. Gently slide the pie onto the preheated baking stone and bake for 20 minutes. Brush the crust with olive oil and bake for 20 more minutes until the crust is crisp and lightly golden.
13. Slice and serve. Enjoy!