Add flour to butter and turn the mixture into crumbs. The easiest way to do this is with a blender. You can also cut the butter and flour mixture with a knife.
Add water to the butter mixture and knead the heterogeneous dough. If you’re mixing the dough in a blender, wait until the dough forms a ball after adding water then finish mixing. If you kneaded the dough with a knife, start kneading it with your hands after adding the water. Don’t knead it for too long.
Roll out the dough to a thickness of 2 mm on a sheet of baking paper.
Remove the cores from the apples and cut into thin slices. Do not peel them.
Select 6-8 nuts, the most beautiful ones, and chop the rest finely.
Place the sliced apples on top of the dough leaving 3 cm from the edge.
Then place cheese slices on top of the apples. Sprinkle with pecans.
Using the edges of the paper on which the dough with the filling is laid out, fold the edges of the dough towards the middle, forming a galette.
Lightly beat the yolk with a little water. Brush the edges with the yolk then sprinkle them with brown sugar.
Bake for 30 minutes or until the edges of the galette will brown nicely.