To make the crust: Add the flour, salt, and sugar to a large mixing bowl. Cut the butter into small cubes and add to the mixing bowl. Use clean dry hands to rub the butter into the flour until it is about the size of a pea. Mix the pastry with a knife in a few tablespoons of ice water. Form the dough into a ball and knead for 30 seconds on a floured surface until smooth.
Wrap the pastry dough in plastic wrap and place it in the fridge for at least 30 minutes to rest.
When you are ready to roll out the pastry, remove it from the fridge and leave it for 5-10 minutes to warm up before rolling it out. Divide the dough in half, roll out the bottom shell, and place it in your pie pan.
In a large bowl add thinly sliced pears, cranberries, sugar, cornstarch, salt, grated ginger, grated orange zest, and orange juice. Mix well. Pour pie into prepared pie crust. Top with a lattice to your liking or just place the entire dough piece over the pie filling.
In a small bowl, whisk together egg + milk. Brush egg mixture over visible pie crust. Place a pan under the pie and bake for 60-75 minutes or until the crust is golden brown and the fruit mixture is bubbling. If you find that the pears are producing too much liquid as the pie bakes, pour or siphon a little off and return to the oven.
Allow to cool slightly before serving. Garnish with whip cream and store covered in the fridge for up to a week.