Preheat the oven to 375. Line a baking sheet with a piece of parchment paper.
On a lightly floured surface, roll out the dough into a circle, about 1/8 inch thick; if you like, trim the rough edges a little for a more even, pretty edge. Set the dough on the baking sheet.
In a bowl, toss the cherries with the 1/4 cup sugar, flour and ginger until well combined. Stir in the cherry jam. Pile the fruit onto the dough, leaving two inches of dough all around. Fold the edges of the dough up, so that it folds up over the fruit. Brush the edges of the dough with the egg white, using it to help seal all the folds together. Sprinkle the dough with the 1 teaspoon sugar. Chill in the refrigerator for 20 minutes.
Bake for about 45 minutes on the center rack in the oven, until the fruit and juices are bubbling and thick, and the crust is golden brown (if needed, lay a piece of aluminum foil over the galette about 30 minutes into baking, to prevent over-browning). Cool for 3-4 hours before cutting into wedges and serving. If desired, garnish the top with the candied ginger and orange zest.
Notes
Click for Pie Dough RecipeStore leftovers at room temperature, covered loosely, for up to 2 days. Pie is best eaten the day it's made, though.
Keyword All Butter Flaky Pie Dough, Cherry Galette, Orange