10tablespoonsbutter(cold and cut into 1 inch pieces)
⅛cupcold ice water
½tablespoonapple cider vinegar
3cupspeaches(peeled and sliced)
3cupsrhubarb(sliced into thin slices)
In the bowl of a food processor, combine flour, sugar and salt. Add cold butter and pulse until the mixture resembles coarse sand with some larger pieces of butter. Add ice water and vinegar and pulse until it comes together. Place in plastic wrap and refrigerate for 2 hours or freeze for 1 hour.
Preheat oven to 400º. Use a rimmed baking sheet.
Roll out pastry onto a sheet of parchment paper into a circle about ¼ inch thick. If it gets to warm to handle, place in the refrigerator for a few minutes.
In a large bowl, whisk together the sugars, salt and cornstarch. Add rhubarb and peaches and stir until combined. Spoon the fruit over the pastry leaving a 1-2 inch border. Pull up sides over the edge of the fruit.
Whisk egg and 1 tablespoon of water and brush over the crust. Sprinkle with sanding sugar.
Bake for 45 minutes until the rhubarb has softened and the crust is golden brown. If the crust begins to get to brown, cover with foil.
Let cool slightly before cutting.
Barbara's Notes + Tips
Place a pan under the galette in the oven in case it oozes out of the pastry
Don't overfill the pie crust.
If the crust is starting to brown and the rhubarb is not soft, cover the crust with aluminum foil.
If the dough gets too warm it can be hard to form. Place it in the refrigerator for a few minutes before assembling.
If your fruit is very juicy, add a little more cornstarch.
Let the galette sit for a few minutes before serving, the filling will thicken as it cools making it easier to slice.