The impressive dessert is ready to go into the oven in 15 minutes. It's a perfect tart to serve when guests drop by.
1. Heat oven to 375 degrees . Line a large baking sheet with nonstick foil. Prepare Filling: In a medium-size bowl, toss together the plums, blueberries, granulated sugar and cornstarch. Set aside.Prepare Crust:
2. In a large bowl, combine piecrust mix, granulated sugar, ginger and 1/3 cup water. Stir until mixture begins to come together, then roll out to a 13-inch circle on a lightly floured surface. Carefully roll up onto rolling pin and transfer to prepared baking sheet.
3. Spoon filling onto center of crust, leaving a 3-inch border all around. Fold edge of crust partway over plum mixture. Brush with beaten egg.
4. Bake galette at 375 degrees for 35 minutes, until crust is browned and center bubbly (some juices may leak out of the crust). Run a thin spatula under galette, then carefully transfer to a serving platter, using 2 spatulas to balance.
5. In a small bowl, mix together the confectioners sugar and 1 tablespoon water. Drizzle over galette and serve.