Mulberry & Strawberry Galette

To make the pastry: In a small bowl, whisk together the egg yolk and water, set aside. Place the flours, potato starch, sugar, and salt in the bowl of a food processor fitted with a steel blade. Pulse a few times to combine. Add the butter and pulse until the mixture resembles a coarse meal. Sprinkle on the egg mixture and pulse until the dough just barely comes together. Turn the dough out onto a board, roll it into a ball, and form into a disk. Wrap the disk in plastic and refrigerate until chilled, about 30-45 minutes.

To make the berry filling: Toss together the berries, sugar, vanilla bean seeds, and lemon zest in a medium bowl. Set aside while the dough chills.

Preheat the oven to 425 F. Line a baking sheet with parchment paper.

Roll the pastry into a 12-inch circle on a lightly floured surface. Transfer it to the baking sheet.

Place the mixed berries on the dough circle, leaving a 1 1/2-inch border. Fold the edge of the dough up and over the berries. Chill the galette in the refrigerator for 15 minutes.

Bake the berry galette for 30-35 minutes, until the crust is golden and the filling is bubbling. Let the galette cool for 10-15 minutes. Dust with powdered sugar then cut into wedges and serve warm or at room temperature.