For the dough, put flour with sugar, 2 tablespoons of cold water and butter in pieces in a bowl. Knead first with the dough hooks of the mixer, then with your hands quickly to a smooth dough. In a greased, flour-dusted tart mould with a lifting base (26 cm Ø), press it down with your hands to a base, forming a rim. This is how it works: you need a tart mould with a wide, flat rim. Grease and dust with flour, push the dough a little over the rim and press in depressions all around with your fingers. Chill for at least 30 minutes.
Wash the nectarines, cut them into slices from the stone. Select blueberries and wash if necessary. Stir the jelly until smooth. Mix fruit and starch, then carefully fold in the jelly.
Sprinkle the dough base evenly with almonds. Spread fruit on top. Bake in the preheated oven (electric cooker: 200 °C/circulating air: 180 °C/gas: see manufacturer) for approx. 40 minutes. Let it cool down.