390 g (18 oz) apples; Golden Delicious or similar (firmer and crispier)
1 egg (L), beaten, plus ½ teaspoon water (for egg wash)
2 tablespoons peach or apricot jam
Method
Sweet tart dough (sweet shortcrust pastry or pâte sablée): See recipe here. This recipe calls for a partially baked crust.
Applesauce:
Wash, core and cut the apples into medium size chunks.
Place the apples into a wide pan, pour ¼ cup (60 ml) of the water and brown sugar and stir. Cover the pan and put it over medium-low heat for 15-20 minutes, stirring with a wooden spoon from time to time.
In the event the water is boiling away, add some more water by driblets to prevent the apples from scorching.
Once the apples are soft enough to be mashed with the wooden spoon, remove from the heat and pass them through a food mill or press them through a sturdy strainer to get rid the of peels and any seeds left into a large bowl.
Taste the sauce and add some granulated sugar (to taste) if necessary, one tablespoon at a time, and stir to combine completely (this sauce is traditionally a little bit tart). If the applesauce seems too runny, return to the heat and cook it for a few more minutes until desired consistency.
Cover with plastic wrap against the surface and keep it in the fridge. (It keeps for up to 4 days tightly covered and refrigerated.)
Place tart pan on a baking sheet and bake for 45-50 minutes until apples are tender and edges are golden brown.
Meanwhile, warm the apricot or peach jam.
Remove tart from the oven and brush a thin layer with the still warm jam with a pastry brush (if the jam were a bit lumpy, previously pass it through a strainer).