1. Make the pie crusts. Whisk together the flour and salt. Using a pastry cutter or two forks, cut in the shortening and butter until the mixture resembles pea-like crumbs. One tablespoon at a time, sprinkle the ice water over the flour mixture and stir with a wooden spoon. Stir and sprinkle ice water until a ball of dough begins to form and the mixture can be easily pinched between two fingers without crumbling apart. Divide the dough into two equal pieces and wrap both pieces tightly in plastic wrap, keeping them refrigerated for at least an hour.
2. Prepare the pie filling. In one bowl large mixing bowl, combine the sliced apples with both sugars, the cinnamon, ginger and nutmeg. Stir together and let it sit for one hour. In another bowl, combine the strawberries, sugar and lemon juice and allow it to sit for the same amount of time as the apples.
   1. When the hour is up, preheat the oven to 400 F. Drain the liquid from both fruits into a saucepan set over medium-high heat on the stove. Combine the apples and strawberries together in one bowl. Make a slurry of 2 tablespoons cornstarch with 1/4 cup water, then simmer it together with the liquid from the fruits, cooking until the liquid is reduced by half, about 10-15 minutes. Once reduced, add the liquid back to the fruits, and stir together.
3. Butter or grease a 9 or 10″ pie plate and roll out one pie crust to a 12″ circle. Place this circle gently into the buttered pie plate, trimming the edges with a sharp knife. Empty the strawberry apple filling into the crust. Dot the top of the filling with the diced butter pieces. Roll out the second pie crust, and either plate it right on top of the filling, or cut it into strips to create a lattice. If placing the crust directly on top, cut a few slits into the top to allow steam to vent. Pinch the edges of the crusts together, sealing them. Using a pastry brush, cover the top crust with the beaten egg. If desired, sprinkle the top of the pie with a bit of sugar.
4. Bake the pie in the oven for 40-45 minutes, or until the pie filling is thick and bubbly and the crust is lightly browned. If the crust is browning too quickly, loosely cover the pie with aluminum foil for the remaining bake time. Remove the pie from the oven and allow it to cool for at least an hour, before serving. This will ensure everything thickens up nicely. Serve with vanilla ice cream!

Leftover pie can be kept in the fridge, in an airtight container, for 2-3 days. Pie can also be frozen for up to 2 months.