Combine salt with cornstarch in a mixing bowl. Add ¼ cup of cold butter, and work the mixture using your hands.

Pour the cold water on top and keep working the mixture until the dough melds together.

Cover the dough with plastic wrap and transfer to your fridge. Let it sit for half an hour.

Combine the peaches, sugar, cinnamon, nutmeg, ginger, and flour in a mixing bowl.

Mix until the peaches are coated.

Melt ½ cup cold butter in a saucepan and add the peach mixture.

Cook until bubbly, which should take 10 minutes.

Transfer the cooked peach mixture to the baking pan.

Cut the now-chilled dough into 8 strips and lay them on top of the peach filling, in a crisscross pattern.

Brush with the beaten egg.

Bake for 45 minutes. Remove from the heat and let it rest for another 45 minutes before serving.