Savory Pastrami and Cheese Pie

1. 1
   Combine the flours, caraway seeds, salt, and pepper in a large bowl and whisk until the mixture is aerated. Add the butter and toss with your fingers until well coated in the flour mixture. Using a pastry blender or your fingers, cut the butter into the dry ingredients until it’s in pea-size pieces, about 4 to 5 minutes.
2. 2
   Drizzle in 3/4 cup of the ice water and mix just until the dough comes together. (Add the last 2 tablespoons of ice water if necessary, but do not overwork the dough or it will become tough.)
3. 3
   Turn out the mixture onto a clean work surface and knead just until any dry pieces are incorporated, about 20 seconds. (Do not overwork the dough.) Divide the dough into 2 flat disks, one slightly larger than the other. Wrap each disk tightly in plastic wrap and refrigerate for at least 1 hour.

For the filling:

1. 1
   Bring a small saucepan of heavily salted water to a boil over high heat. Add the potatoes and cook until knife tender, about 5 minutes. Drain in a colander and transfer to a medium bowl; set aside.
2. 2
   Melt the butter in a large frying pan over high heat until foaming. Add the pastrami and cook, stirring occasionally with a wooden spoon, until browned, about 5 minutes. Reduce the heat to medium low, remove the pastrami with a slotted spoon to the bowl with the potatoes, and set aside.
3. 3
   Add the onion to the pan and season with salt and pepper. Cook, stirring occasionally, until softened, about 5 minutes. Add the Brussels sprouts and season with salt and pepper. Sprinkle in the flour and cook, stirring occasionally, until the raw flavor has cooked off, about 1 to 2 minutes.
4. 4
   Add the chicken broth, mustard, and vinegar and stir to combine, scraping up any browned bits from the bottom of the pan. Cook until the liquid just comes to a simmer and thickens, about 1 minute. Remove the pan from the heat and stir in the reserved potatoes and pastrami. Taste the filling and season with salt and pepper as needed; set aside.

To assemble:

1. 1
   Remove the dough from the refrigerator and set aside. Heat the oven to 450°F and arrange a rack in the lower third. Line a baking sheet with aluminum foil and place it on the rack while the oven is heating.
2. 2
   On a lightly floured surface, roll out the slightly larger disk of dough to about 13 inches in diameter and 1/4 inch thick. (Don’t worry if the dough cracks—just press it back together.) Line a 9-1/2-inch deep-dish pie plate with the dough and trim it to leave a 1-inch overhang.
3. 3
   Roll out the remaining disk of dough on a lightly floured surface to about 12 inches in diameter and 1/4 inch thick.
4. 4
   Brush the overhang of the crust in the pie plate with a thin layer of the milk, half-and-half, or cream. Add the filling and smooth it into an even layer. Sprinkle the cheese over the filling and cover with the 12-inch sheet of dough. Trim the excess dough from the top crust to match the overhang of the bottom crust. Press the edges of the bottom and top crusts together with your fingers.
5. 5
   Using your fingers or the back of a fork, crimp the dough to seal it tightly. With a sharp knife, cut 6 slits in the top crust, evenly spaced and radiating out from the center. Brush the top of the pie with the remaining milk, half-and-half, or cream.
6. 6
   Place the pie on the hot baking sheet and bake for 20 minutes. Reduce the oven temperature to 350°F and bake until the pie crust is golden brown and the filling is bubbling, about 50 minutes more. Remove from the oven and let sit on a wire rack on the baking sheet to cool for 20 minutes before serving.