In a mixing bowl, combine the flour, salt, and sugar. Mix well to ensure even distribution of ingredients.

Add the cold, cubed butter to the flour mixture. Using a pastry cutter or your fingers, work the butter into the flour until the mixture resembles coarse crumbs.

Gradually add the ice water, one tablespoon at a time, mixing gently until the dough comes together. Be careful not to overwork the dough.

Divide the dough in half, shape each half into a disk, wrap in plastic wrap, and refrigerate for at least 1 hour.

In a large mixing bowl, combine the sliced peaches, sugar, flour, cinnamon, and lemon juice. Toss gently to coat the peaches evenly.

Let the filling sit for about 15 minutes to allow the juices to release.

Preheat your oven to 425°F (220°C).

On a floured surface, roll out one disk of the chilled dough into a circle about 12 inches in diameter. Carefully transfer it to the pie dish.

Pour the peach filling into the pie crust, spreading it evenly. Dot the filling with small pieces of butter.

Roll out the second disk of dough and place it over the filling. Trim any excess dough and crimp the edges to seal.

Cut a few slits in the top crust to allow steam to escape.

In a small bowl, whisk together the beaten egg and water. Brush the egg wash over the top crust for a golden finish.

Place the pie on a baking sheet to catch any drips and bake in the preheated oven for 45-50 minutes, or until the crust is golden brown and the filling is bubbling.

If the edges brown too quickly, cover them with foil.

Once baked, remove the pie from the oven and let it cool for at least 2 hours before slicing to allow the filling to set.