In a large bowl, combine the Céliane bread mix , the Céliane potato starch and the almond powder. Add 120 g of butter in small pieces and work the mixture until you obtain a sandy consistency.

Add 80 g of sugar, an egg and a pinch of salt. Continue to work the dough until it forms a uniform ball. If the dough is too sticky, add a little Céliane bread mix.

Wrap the ball of dough in cling film and let it rest in the refrigerator for about 60 minutes.

After an hour, preheat your oven to 180°C (thermostat 6).

Prepare the tart base by rolling it out with a rolling pin until it is 5 to 7 millimeters thick, then place it in a previously buttered and floured tart mold.

Wash, peel, core and cut the apples into slices about 2.5 cm thick. Mix them with 150 g of brown sugar, the rest of the bread mix, the nutmeg, cinnamon and salt.

Arrange the apple slices in the pan, stacking them lightly in the center. Sprinkle with 30 g of diced butter.

Cut the rest of your shortbread dough into strips approximately 2 cm wide. Weave a grid pattern across the top of the pie and seal the edges with a fork.

Beat an egg yolk and brush the grid and the edges of the tart. Sprinkle the tart with a little sugar then bake for 45 to 50 minutes. Let the apple pie cool before serving.