8 tablespoons (1 stick) unsalted butter, cut into small pieces (about the size of dice)
¼ cup sour cream
2 teaspoons fresh lemon juice
¼ cup ice water
For the Peach Filling:
3 cups thinly sliced peaches (about 3 large)
½ cup light brown sugar
1 teaspoon ground cinnamon
1 teaspoon pure vanilla extract
2 tablespoons cornstarch
1 egg white
2 tablespoons turbinado sugar
Instructions
Make the pastry: In a bowl, combine the flour and salt. Add the butter to the mixture and using a pastry blender (or your fingers – it works, I swear!) cut it in until the mixture resembles coarse meal (you should be left with small lumps of butter no larger than the size of individual peas).
Center a rack in the oven and preheat to 350 degrees F. In a separate small bowl, whisk together the sour cream, lemon juice and water and add half of this mixture to the well. With your fingertips (this recipe is not for the newly-manicured) mix in the sour cream mixture until lumps form. Remove the large lumps and repeat with the remaining liquid. Pat the lumps together to form them into a ball and place in a bowl covered with plastic wrap. Refrigerate for one hour to chill dough – this will make it less sticky when it’s time to roll out.
To make the peach filling, combine all ingredients in a large bowl, and toss gently, making sure that the cornstarch is coating the fruit. When the peaches cook, they'll release liquid and the cornstarch will keep those juices nice and thick.
Preheat your oven to 375 degrees F. Once dough has chilled, remove it from the refrigerator and on a floured work surface, roll the dough out into a 12-inch round. Transfer to an ungreased baking sheet covered with parchment paper or silpat. Spread peach mixture over dough, leaving a 1½-inch border. Brush dough with egg wash, and sprinkle with turbinado sugar.
Bake for 1 hour, or until crust is golden brown and the filling is bubbly. Serve warm or at room temperature. This will keep for up to 3 days, so you can make it in advance for a party (but don't expect it to last that long).
Recipe by In Good Taste at http://ingoodtaste.kitchen/lazy-summer-dessert-rustic-peach-galette/