Rhubarb and Rose Galettes

In a large bowl, use your fingers to rub the vanilla seeds and lemon zest into the sugar, then add the flour and salt. Add the rhubarb batons to the bowl along with the lemon juice and rose water. Toss the rhubarb with the sugar and flour mixture to coat.

Remove one square of the pie dough from the refrigerator and cut it into quarters. On a lightly floured surface, roll each dough quarter into a 4 by 5-inch rectangle between 1⁄8 to 1⁄4-inch thick. Transfer the four rectangles of dough to one of the prepared baking sheets. Arrange one-eighth of the rhubarb batons in a single, slightly overlapping layer on each piece of dough, leaving a generous 1⁄2-inch border around all sides. Fold the excess dough up and over the rhubarb and press the corner seams gently with your fingers to seal. Put the baking sheet in the freezer and repeat with the remaining dough and rhubarb. Place that baking sheet in the freezer, too, and freeze until the dough is very firm, about 15 minutes. Save any rhubarb juices that remain in the bottom of the bowl.

While the galettes are chilling, position two racks in the center and lower third of the oven, and preheat to 425ºF (220ºF/Gas Mark 7). When you are ready to bake the galettes, brush the edges of each galette with the egg wash and sprinkle with turbinado sugar. Top the rhubarb in each galette with a spoonful of the reserved rhubarb juices. Bake the galettes, rotating the pans from top to bottom and front to back halfway through baking, until they are deep golden brown and crisp, 30 to 40 minutes.

To make the rose cream: Whip the cream with the rose water and sugar until soft peaks form. Store the cream in the refrigerator until ready to serve. Let the tarts cool slightly before serving. Top each tart with a spoonful of cream and serve immediately.