For the shortcrust pastry, stir together the sugar and butter until foamy. Mix the egg, the grated zest of the lemon and a pinch of salt. Stir in the flour. Shape the dough into a ball and refrigerate for 30 minutes.
For the crumble mix the flour and sugar. Add the butter in flakes and mix everything with a hand mixer or by hand into sprinkles of the desired size. Chill too.
Line a tart pan with the shortcrust pastry, pull up the edge. Prick the dough several times with a fork. Cover with baking paper and blindly bake with blind baking balls or legumes for about 15 minutes at 200 ° degrees.
In the meantime, stir the ingredients for the filling without the berries. Put the mixture on the pre-baked base, then spread the blueberries on top. Finally, distribute the crumble evenly on the tart. Bake in a preheated oven with convection: 175 ° degrees approx. 30 - 35.