Preheat the oven (electric cooker: 160 °C). Spread 150 g sliced almonds and pistachios on a baking tray and roast them in the oven for about 10 minutes.
Finely grind the almonds and pistachios in a food processor. Add sugar and salt and grind further. Add eggs, butter, vanilla extract and almond flavour and mix to a spreadable cream.
Increase oven temperature (electric stove) to 220 °C. Roll out the puff pastry and cut through once crosswise. Place the dough sheets on top of each other to form a square. First roll out and then roll the edge of the dough slightly with your fingers 1-2 cm inwards to create a round shape.
Pick the dough several times with a fork. Place the dough with the baking paper on a baking tray and pre-bake in the top third of the oven for about 8 minutes. Remove from the oven and allow to collapse again easily.
Switch the oven (electric cooker) down to 180 °C.
Spread a thin layer of pistachio cream on the pastry base. Place nectarine slices fan-shaped on the cream and sprinkle with 1 tbsp. sliced almonds and brown sugar. Bake the tart for 35-40 minutes.
Let it cool down.