• Preheat the oven to 425 degrees F.

Make the pie / galette dough

• Mix the dry ingredients and add the butter. Cut the butter into pie size cubes with 2 knives, a pastry cutter or do it in a food processor.
• Add the egg yolk and mix again.
• Add 5 tablespoons of cold water and mix. Add more water if necessary, 1 tablespoon at a time, until the mixture holds together. Do not overmix.
• Wrap the dough in plastic wrap and cool in the fridge until you're ready with the peach filling.

Make the peach filling

• Peel the peaches if you prefer to do so. (NOTE 1)
• Cut the peach in half, discard the pit and slice each half in 4-5 slice, depending on the size of the peaches. (NOTE 2)
• Add the sugar and set the peaches aside.

Construct the galette

• Take the dough out of the fridge and roll it out on parchment paper or a baking mat. Roll it out into a circle of approx. 1/8-inch thickness.
• Before you transfer the peach slices onto the dough taste them. Decide whether you like to add some vanilla flavor. Also check the amount of liquid. If a lot of liquid was released from the peaches, you may want to add the cornstarch as it will absorb some of that liquid.
• Transfer peach slices onto the dough and leave a border of about 2 inches.
• Fold the edges of the dough over the peaches until you made full circle.
• Brush the edge with egg white and sprinkle with turbinado sugar.

Bake the galette

• Transfer the galette into the heated oven and bake for approx. 20 minutes.
• The Whole What White Peach Pie is done when the dough is nice and brown and the filling show bubbly.

How to serve

• Serve cool or warm with a dollop of whipped cream or a scoop of ice cream.