I start by whisking the flour and salt together, then cutting in the cold butter until it looks like coarse crumbs. I add ice water a tablespoon at a time until the dough just holds together. I shape it into a disc, wrap it, and chill it for at least an hour.
While the dough chills, I toss my sliced pears with sugar, cornstarch, lemon juice, vanilla, and cinnamon in a bowl. I let this sit for about ten minutes so the pears release a little juice and soak up the flavors evenly.
Once the dough is firm, I roll it into a rough 12-inch circle on a lightly floured surface. It doesn't need to be perfectly round, that's the beauty of a galette. I transfer it carefully onto my parchment-lined baking sheet.
I layer the pear slices in the center of the dough, slightly overlapping them in a circular pattern, leaving about a 2-inch border of dough all around. I pour any leftover juices from the bowl right over the top.
Next, I fold the edges of the dough over the pears, pleating as I go to create that classic rustic look. I pop the whole tray into the fridge for 15 minutes so the butter firms back up before baking.
I brush the crust with egg wash and sprinkle coarse sugar on top, then bake at 400°F for 35-40 minutes until the crust is deep golden brown and the pears are tender. I let it cool slightly on the pan before slicing.