prepare the pie crust

1. Cut the butter into quarter-inch cubes. Place the butter in the freezer for at least ten minutes or until ready to use.
2. Pulse together the flour, sugar and salt in a food processor, once or twice until just combined. Add the butter cubes to the flour mixture and pulse a few times until the butter is evenly distributed, with the largest butter bits about the size of large peas.
3. Add the vinegar and ice water, pulsing once or twice between each tablespoon addition. The dough is ready when it appears crumbly, but will easily hold together when pinched between two fingers.
4. Turn the dough out onto a clean, lightly floured work surface. Form into a round, flat disk, working quickly and being careful not to over-handle the dough.
5. Wrap the disk tightly in plastic wrap. Refrigerate the dough for at least an hour prior to rolling it out. The pastry may be made in advance and stored for up to a day in the refrigerator or – if wrapped very tightly in plastic wrap – about a month in the freezer.

make the blueberry galette

1. Prepare the pie pastry: Remove the dough from the fridge. Wait about 10 minutes for the dough to warm slightly and become pliable.
2. Meanwhile, preheat the oven to 375℉. Line a large rimmed sheet pan with parchment paper. Set aside.
3. Place the dough in the center of a clean, lightly floured work surface. Using a rolling pin – I prefer to use a French (tapered) rolling pin – start in the center of the disk, and roll outwards, with firm but gentle pressure. Turn the dough and continue rolling towards the edges. As you work, don’t be afraid to sprinkle additional flour on top of the dough and underneath, as well as on the rolling pin to avoid sticking.
4. Continue rolling until the dough is about 12 inches in diameter and about 1/8-inch thick. As the dough gets larger, be careful to apply even pressure with the rolling pin across the entire surface of the dough.
5. Gently transfer the dough to the sheet pan, being careful not to pull or tear the dough. Place in the fridge while you prepare the filling.
6. Prepare the blueberry filling: In a large mixing bowl, toss together the blueberries with the sugar, lemon, vanilla, and arrowroot starch, until well-combined.
7. Assemble the galette: Spoon the blueberries onto the center of the pie pastry, in an even layer,leaving about two inches around the edge. Fold the pastry over the berries, overlapping the dough as needed.
8. Brush the pastry with the egg wash or cream and generously sprinkle with the demerara sugar.
9. Bake for 40-50 minutes, until the pastry is golden and the berry juices begin to bubble. If the crust begins to brown too quickly, cover loosely with aluminum foil.
10. Remove from the oven and allow to cool to room-temperature on a baking rack until set. Serve warm with a dusting of confectioners sugar or a scoop of vanilla ice cream. Enjoy!