Apple-Walnut Galette

Directions

1. 1
   Position racks in the middle and lower third of the oven; preheat to 350 degrees F. Make the dough: Pulse the flour, granulated sugar and salt in a food processor until combined.
2. 2
   Add the butter; pulse until the mixture looks like coarse meal with pea-size bits of butter.
3. 3
   Beat the egg with 1 tablespoon ice water in a bowl, then add to the processor and pulse once or twice.
4. 4
   (Stop before the dough gathers into a ball.)
5. 5
   Turn out onto a sheet of plastic wrap and pat into a disk.
6. 6
   Wrap tightly and refrigerate until firm, at least 1 hour.
7. 7
   Meanwhile, prepare the filling: Toast the walnuts on a baking sheet on the middle oven rack until golden, 7 to 8 minutes; let cool.
8. 8
   Process the nuts, 1/4 cup granulated sugar, the egg, 1 tablespoon butter, the vanilla and salt in a clean food processor to make a creamy paste.
9. 9
   Line a flat baking sheet (or an upside-down rimmed one) with parchment paper.
10. 10
    Roll the dough into a 12-inch round on a floured surface.
11. 11
    Roll the dough up onto the rolling pin, then unroll onto the parchment.
12. 12
    Spread the walnut filling over the dough, leaving a 1 1/2-inch border around the edges.
13. 13
    Chill while you prepare the apples.
14. 14
    Increase the oven temperature to 400 degrees F. Peel, core and halve the apples, then cut each half into 8 wedges.
15. 15
    Arrange over the filling in a circular pattern, slightly overlapping.
16. 16
    Fold the edges of the dough inward, pleating it.
17. 17
    Sprinkle the apples with the remaining 1 tablespoon granulated sugar and 2 tablespoons butter.
18. 18
    Bake the galette on the middle oven rack until golden, 40 to 45 minutes.
19. 19
    (Put a baking sheet on the lower rack to catch any drips.)
20. 20
    Cool on a rack.
21. 21
    Whisk 1 tablespoon water and the preserves in a bowl.
22. 22
    Strain, then brush over the apples.
23. 23
    Dust with confectioners' sugar, if desired.
24. 24
    Photographs by Con Poulos