4tablespoons(1/2 stick) cold unsalted buttercut into 1/2 inch pieces
For the filling:
2cupsmixed berriesI used strawberries and blueberries
Preheat the oven to 400° F.
In a medium bowl, stir together the flour, cornmeal, sugar and salt. Using a pastry cutter or two forks, cut in the butter until the mixture resembles course crumbs. If you wish, this can also be done in a food processor. Whisk together the egg yolk with the water. Slowly drizzle in the egg yolk/water mixture, about tablespoon at a time and toss with a fork until the dough just comes together. It will still be crumbly (take care not to make the dough too wet). Place in the center of a sheet of plastic wrap, using the wrap to bring it into the shape of a ball, wrapping as you go. Press it into a disk form and chill in the refrigerator for at least 30 minutes.
Toss the fruit in a bowl with the sugar and cornstarch and set aside as you shape the dough.
Place the dough between two sheets of parchment paper and roll out into a disk about 9 1/2 inches wide and 1/8 inch thick. It does not have to be perfect. Arrange the fruit in the center of the disk. Gently bring up the edges of the dough, folding and crimping a little along the way towards the center of the galette. Lightly brush the exposed dough with the egg white. Sprinkle the washed dough with sugar, if you wish.
Transfer the galette on the parchment to a cast iron skillet or baking sheet. Bake for about 40 minutes, or until the center is bubbly and the crust is golden brown. Remove from the oven when it is fully baked, and transfer to a cooling rack. Warm the apricot jam with a teaspoon of water in the microwave and whisk well. Brush the jam on the berries to bring back its shine.
When the filling has had some time to rest, slice the galette and enjoy, either plain, with some whipped cream, Greek yogurt, or a la mode.
Cornmeal crust lightly adapted from Cornmeal Pastry, The Martha Stewart Living Cookbook (Oxmoor House, 2000).