PIE CRUST - In a bowl, mix flour and salt, then cut chilled butter into mixture. Create a crumbly mixture by breaking the butter and combining with flour.
Once you have finer crumbles, begin adding iced water (a tablespoon or two at a time) and continue mixing until larger clumps are formed. Combine gently into dough ball.
Turn out onto a floured surface and gently knead dough into a rough disc. Wrap in plastic and let chill for 30 minutes in fridge or 15 minutes in freezer.
Preheat oven to 375°F and line a baking sheet with parchment.
FRUIT FILLING - Thinly slice peaches and place in a large bowl. Add sugar, cornstarch, cinnamon, and lemon juice. Mix well until combined.
Roll out pie dough to large 11" round(ish) shape. Place dough on parchment lined baking sheet.
Before spooning peaches onto dough, be sure to sprinkle a layer of flour on your dough round in the center where the fruit will go. This will keep your dough from getting soggy in the middle bottom.
Spoon peaches into center of dough, leaving a 2-3" border.
Fold dough over and pinch to enclose peaches, leaving the center open.
Brush crust with egg wash and sprinkle with coarse sugar.
Bake for 35-45mins, until crust is golden and juices are bubbling.
Cool on sheet for 10mins before serving. Optionally dust with powdered sugar once it's cooled.
Store in fridge. Serve cold or reheated, on it's own or with ice cream or whipped cream.