In a food processor add flour, cornmeal, sugar, butter, and salt. Pulse until combined and mixture looks like course sand. Add 2 tablespoons of cold ice water (minus the ice). Pulse to combine. If the dough still looks like coarse sand keep adding water one tablespoon at a time until the dough starts to come together when pinched. The amount of water used depends on the humidity of the day. Some days I use 3 tablespoons and others 5. Note: This can be done without a food processor. Mix ingredients in a large bowl. Work water in using a fork.
Press dough together to form a disk. Wrap in plastic wrap and place in the refrigerator for 2 hours. If you are in a hurry place in the freezer for 30 minutes but the fridge is best.
When the dough has chilled preheat the oven to 425°F and grease a 10 inch pie plate or tin. Slice peaces in half, remove the pit, and slice peaches into small cubes. There is no need to peel the peaches. Place the peaches in a large bowl with the remaining ingredients for the filling. Stir to combine.
On a clean dry work surface, throw a little flour down. Place the chilled dough on the flour and add an additional bit of flour on top of the dough. Using a rolling pin, roll out the dough to a 12 inch round. It’s ok if it cracks on the edges. Place the rolled dough into a greased 10 inch pie plate or tin.
Pour the peach filling into the dough. Simply fold the dough up and over the edge of the fruit. Place in the oven and bake for 45 to 50 minuted until the crust is golden.
Allow to cool completely before serving. This will give the filling time to set. Best served at room temperature.