Spoon the apple filling into the center of the dough, leaving a 2-inch (5 cm) border around the edges. Fold the edges over the apples. Brush the egg wash over the crust and sprinkle coarse sugar all over the galette. Bake the galette for 25 minutes, until the crust is golden brown.
This keto apple tart is easier to make than a pie, and has the perfect apple to crust ratio for keeping it low carb. If you love apple desserts, then this is one that you can enjoy any time of year, even when apples aren’t at their peak. Growing up in New England, apples in the fall were a big deal.
Shape the dough into a rough ball and cover with plastic wrap. Chill in the refrigerator for 30 minutes. Meanwhile, make the apple filling: In a large skillet over medium heat, combine the sliced apples, lemon juice, cinnamon, and sugar. Cook, stirring continuously, until the apples are soft, about 10 minutes.