Place the puff pastry slices next to each other and let them thaw at room temperature. Grease 4 Tartelette moulds with lift-off base (approx. 12 cm Ø) and dust with flour. Pour the dough into the greased Tartelette cups, press down the edges and prick several times with a fork.
Cut off excess dough at the edge with a knife.
Cut baking paper to the size of the baking tins. Cover the puff pastry with baking parchment, add dried peas. Bake in a preheated oven (electric cooker: 200 °C/ circulating air: 175 °C/ gas: see manufacturer) for approx. 12 minutes until blind.
Take out, remove dry peas. Let the Tartelettes cool in the moulds.
Peel apples, leaving the stalk standing. Hollow out the apple from the flower with a ball cutter. Boil up white wine, apple juice, sugar and saffron. Add apples and simmer for about 15 minutes.
Remove the apples from the stock with a skimmer and let them cool down.
Melt the couverture over a warm water bath. Soak gelatine in cold water. Whip the cream with the whisk of the hand mixer until stiff. Fold cream by the spoonful into the melted couverture.
Squeeze the gelatine, dissolve carefully. Stir in 2-3 tablespoons of cream, then stir everything into the rest of the cream and refrigerate.
Cut the apples several times crosswise from the hollowed side. Cut off a small slice at an angle and fan out the apples. Spread the cream into the tartelettes and place the apples on top. Chill for about 1 hour.
Roast the pistachios in a pan without fat. Take them out, let them cool down and chop them roughly. Sprinkle Tartelettes with pistachios and dust with icing sugar if necessary.