In a bowl, combine all the ingredients for the filling together. Mix until well combined. Set aside.

Preheat the oven to 350F. Line a baking sheet with parchment and set aside.

In a saucepan, heat the water and butter over medium heat until it comes to a simmer. Meanwhile, mix together the flour and salt. Once the water comes to a simmer, pour the liquid into the dries and mix until it forms a ball of dough.

On a lightly floured surface, divide the dough into quarters. Take one quarter and cut off 1/3 of the dough. This will be for the lid.

Using a mold (of a bottle or I used a dry one cup measuring cup), lightly oil or flour the mold so the dough comes off easier later. Press and mold the dough up the sides of the mold until it forms a bowl shape. Refrigerate for 10 minutes or until it dries up a bit. Unmold and repeat with the rest of the pieces of dough.

Place the molded dough onto the prepared baking sheet. Roll out the rest of the dough into a circle for the tops. Cut a small hole in the center for ventilation. Set aside.

Fill the crust with the duck filling. Gently press but do not pack it in. Brush the edges with egg wash and place the lid on top. Press to seal. Brush the top and sides of the pie with egg and baking for 45 minutes at 350F, or until golden brown and the center is bubbling. Let cool.