Jersey Apple & Blackberry Galette with Hazelnut Crumble

**Make the Crust:** In a large bowl, whisk together flour, grated Jersey Royal potato, and 2 tbsp granulated sugar.

Cut in the cold Jersey butter using a pastry blender or your fingers until the mixture resembles coarse crumbs.

Gradually add ice water, one tablespoon at a time, mixing until the dough just comes together. Do not overmix.

Form the dough into a disc, wrap in plastic wrap, and refrigerate for at least 30 minutes.

**Make the Crumble:** In a small bowl, combine chopped hazelnuts, flour, and brown sugar. Cut in the cold Jersey butter until the mixture resembles coarse crumbs. Refrigerate until ready to use.

**Prepare the Filling:** In a large bowl, combine sliced apples, blackberries, 1/4 cup granulated sugar, lemon juice, cornstarch, and cinnamon. Toss gently to coat.

**Assemble the Galette:** Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper.

On a lightly floured surface, roll out the chilled dough into a 12-inch circle. Transfer to the prepared baking sheet.

Pile the apple and blackberry filling in the center of the dough, leaving a 2-inch border.

Carefully fold the edges of the dough over the filling, pleating as you go.

Sprinkle the hazelnut crumble evenly over the filling.

Brush the crust with Jersey milk and sprinkle with turbinado sugar.

Bake for 35-40 minutes, or until the crust is golden brown and the filling is bubbly.

Let cool slightly before serving. Serve warm or at room temperature.