In the bowl of a food processor, add the All-Purpose Flour (2 1/4 cup), Unsalted Butter (1/2 cup), Salt (1/4 teaspoon), and Freshly Ground Black Pepper (1/4 teaspoon). Give it a few quick pulses until the mixture resembles pea-size crumbs.
Add the cut up Cream Cheese (8 ounce) and steadily pulse until it all comes together. That should happen in less than a minute.
Place the dough in a gallon-size resealable plastic bag. Gently smooth it out with a rolling pin to form a rectangle. It helps to be sure that the air is removed from the bag before sealing and rolling.
Place the dough in the refrigerator for at least one hour or until ready to use.
For the filling, heat the Unsalted Butter (2 tablespoon) and Olive Oil (2 tablespoon) over medium-high heat in a medium-large saucepan. Add the Leek (4 cup) and Garlic (2 clove). Cook and stir 3-4 minutes or until tender.
Add the Chicken Broth (1/2 cup) and Dijon Mustard (1 teaspoon). Bring to a boil. Reduce heat and simmer, uncovered, for 1 minute. Remove from the heat.
Stir in cubed Cooked Ham (1 pound), Red Chili Pepper (2 cup), Frozen Green Peas (1 cup), Fresh Oregano (2 tablespoon), and Fresh Parsley (2 tablespoon). Cool for 10 minutes.
Stir in the Gruyère Cheese (1 1/2 cup) and All-Purpose Flour (1/3 cup).
On a floured surface, roll one batch of pastry dough to a 17x12-inch rectangle about 1/8-inch thick. Fold into quarters, then unfold into a 15x10x1-inch baking pan. Ease into sides and corners. Trim to 1/2-inch beyond pan edges. Cover and chill trimmings.
Transfer the filling to the pastry-lined baking pan. Preheat oven to 375 degrees F (190 degrees C).
On a floured surface, roll the second batch of pastry dough to a 17x12-inch rectangle about 1/8-inch thick. Trim to a 15x10-inch rectangle. Reserve trimmings. Fold the pastry into quarters, then unfold over the filling. Fold the edge of bottom pastry over top and pinch to seal. Brush entire surface with Egg (1).
Bake for 50-60 minutes, or until filling is bubbly and crust is golden brown.
Let cool for 10 minutes.
Cut into 10 rectangles to serve. If desired, partially wrap each portion with waxed paper or bakery tissue, then tie with kitchen twine. Serve warm or at room temperature. Pie can sit out for up to 2 hours. Reheat any remaining slices in a 350 degrees F (175 degrees C) oven for 15 minutes.