For the crust: In a large bowl, whisk together the flour, 1 tbsp sugar, and salt. Add the cold, cubed butter. Using a pastry blender, cut the butter into the flour until the mixture resembles coarse meal with some pea-sized pieces of butter remaining. Drizzle in the ice-cold water, one tablespoon at a time, mixing with a fork just until the dough comes together. Form into a disc, wrap tightly in plastic, and refrigerate for at least 1 hour.

Shape the crust: Preheat the oven to 420°F (215°C). On a lightly floured surface, roll the chilled dough into a 12-inch circle. Gently transfer to a standard 9-inch pie dish, pressing it into the bottom and sides without stretching. Trim excess, leaving a 1-inch overhang; fold the overhang under and flute the edges. Chill the shaped shell for 15 minutes.

Blind bake: Line the chilled pie shell with parchment paper and fill it with pie weights or dried beans. Bake for 12 to 15 minutes, until the edges are just golden. Remove weights and paper; bake for an additional 2-3 minutes to set the bottom crust. Cool slightly. **Reduce oven temperature to 375°F (190°C).**

Assemble the pie: Peel, pit, and slice peaches (if fresh) into uniform wedges. Arrange them elegantly (e.g., in concentric circles, 'shingled') in the partially cooled pie crust.

Prepare custard: In a medium bowl, whisk together the eggs, 1/2 cup sugar, heavy cream, vanilla extract, cornstarch, and the pinch of nutmeg until completely smooth and cohesive.

Bake: Place the pie dish on a baking sheet. Carefully pour the custard filling over the peaches in the pie shell. Bake at 375°F (190°C) for 35-45 minutes, until the edges are golden, the custard is puffed, and the center still has a slight jiggle (but isn't sloshy).

Cool and serve: Let the pie cool completely on a wire rack at room temperature (about 1.5 hours). Transfer to the refrigerator for at least 1 hour (ideally 4) to set the custard firmly before slicing. Serve slightly chilled or at room temperature.