adapted from New York Times Recipe Collection
Crust
2 cups all-purpose flour
1 3/4 sticks cold, unsalted butter, cut into pieces
1 Tbsp cold vegetable shortening
Scant 1/2 tsp Kosher salt
Scant 1/2 tsp sugar
1 egg used to make an egg wash to coat the dough prior to baking
Prepare the crust: Combine the flour, butter, shortening, salt and sugar in the bowl of a food processor. Pulse together until the mixture is crumbly and butter is broken into small pieces. Pour 1/3 cup ice water into the bowl. Pulse 3 to 4 times. Test the dough by squeezing in your hand to determine if the clumps together and is evenly moist. If it is not, add and additional tablespoon of water, and pulse once or twice. Do not overmix so that the dough comes together in a ball.
Turn the dough onto plastic wrap. Lift the ends of the wrap to bring the dough together inside. Press it into a large disk, wrap tightly and refrigerate until ready to use. The dough may be made up to two days in advance.
Filling
5 Tbsp unsalted butter
2-3 carrots, peeled, chopped to make 1 cup
1 cup chopped celery
1 cup leeks, cleaned, thinly sliced, white and light green parts only
1 Tbsp chopped fresh tarragon or 1 tsp dried tarragon
1 cup frozen baby green peas
4 Tbsp all-purpose flour
2 1/2 cups chicken stock or broth
1 cup heavy cream
1/4 tsp salt
1/4 tsp freshly ground pepper
3 cups leftover turkey or chicken, cut into 1/2-inch chunks
Prepare the filling: Melt 2 Tbsp butter in a large skillet over medium-high heat. Add carrot, celery, leeks and tarragon and cook, stirring, until slightly softened but not browned (adjust the heat, as necessary, to prevent browning), about 3-5 minutes. Transfer the cooked vegetables to a bowl. Wipe out the skillet.
Melt the remaining 3 Tablespoons butter over medium-high heat. Whick in the flour, and cook, whisking, until the mixture bubbles and smells cooked. Do let let the mixture brown. Whisk in 2 cups of broth. Cook, whisking, about 1 minute. Whisk in the cream, cook until thickened, about 2 to 3 minutes. Add the salt and pepper. If the sauce appears to be too thick, whisk in the additional half cup of stock/broth.
Preheat the oven to 400° F.
Add the cooked vegetables, peas, chicken, and sauce to an 8-inch deep pie dish or small baking dish. Mix gently, adjust seasoning.
Flour a work surface. Remove the dough from the refrigerator. Roll out the dough, turning and flouring often. Cut a shape approximately the size of your baking dish plus 1 1/2 inches overlap all around.
Roll the dough up onto the rolling pin, and unroll evenly over the dish. Fold the edges under and crimp. Create hole vents near the center using a knife or a fork.
Whisk the egg and 1 Tablespoon of cold water together. Using a pastry brush, lightly coat the crust with the egg wash.
Place the dish onto a baking sheet and place in the oven.
Bake 20 minutes, then reduce the oven temperature to 350° F. Bake 25 to 30 minutes longer, until the crust is golden and the filling is bubbling.
Allow the pot pie to rest for 10 minutes before serving.