Cut the puff pastry into rectangles, sprinkle with icing sugar bake in the oven between two baking sheets at 180°C until caramelized.
Make the tangerine mousse:
Mark a sabayon (eggs+icing sugar+mandarin juice+blanched zests+gelatin) and stir in the butter off the heat, cool, whip the cream and add to the mixture to lighten it.
Make the crystallized petals:separate the mandarin segments, drizzle them in syrup flavored with Sechuan pepper, dry in the oven at 80°C.
Assemble the mille-feuille and arrange the petals around it as well as the syrup.
This recipe may seem tedious, but finally once the mousse is made, the puff pastry is cooked, it is very feasible.