You'll see streaks of butter when you gather the dough into a disk, but don't be alarmed. In the oven, those streaks of butter help to create light, flaky, buttery layers. I love frangipane, so I frequently create desserts that satisfy my craving for this sweet, rich almond filling. The crushed cookies in the plum tart do the same. There's no barrier for my savory tart because its ingredients aren't as moist and because the cornmeal crust holds up better.
Chunky butter makes light pastry.
Here the author uses a pastry blender to cut the butter into the flour, but a stand mixer works well, too. Galette assembly is best done on a parchment-lined baking sheet. The parchment makes it easier to slide the baked tart onto a cooling rack. A sprinkling of crushed cookies keeps the crust crisp by absorbing some of the fruits' juices. A layer of frangipane works well, too.