01 -
Cream butter and icing sugar on medium speed until smooth. Mix in egg and ground pistachio, then add sifted flour and salt, mixing until a rough paste forms.
02 -
Place pastry between baking paper sheets and roll into a disk about 4mm thick. Refrigerate for at least 2 hours, or up to 24 hours.
03 -
After chilling, let pastry soften slightly for 5 minutes. Transfer into a 22cm perforated tart ring, pressing edges to fit. Create a clean 90-degree angle at edges and trim excess dough. Cover loosely with baking paper and refrigerate for at least 2 hours, preferably overnight.
04 -
Heat milk to a simmer. Meanwhile, whisk egg yolks and sugar until smooth, then add cornstarch. Gradually pour warm milk into egg mixture while whisking, then return mixture to saucepan over low heat.
05 -
Cook for about 5 minutes, stirring continuously. When large bubbles appear, whisk vigorously for 30 seconds and remove from heat. Add pistachio paste and whisk until smooth. Transfer to a clean bowl, cover with plastic wrap touching the surface, and refrigerate for at least 2 hours.
06 -
Prick the pastry base with a fork and freeze while preheating oven to 160°C/325°F. Blind bake for 15-20 minutes until the bottom appears mostly dry. Set aside to cool.
07 -
Beat softened butter on medium speed for 2-3 minutes until pale and very soft. Add icing sugar and mix to a smooth paste. Incorporate eggs one at a time, then mix in ground pistachio to form a thick, coarse mixture.
08 -
Pour sponge mixture into par-baked tart shell, spreading evenly with an offset spatula. Top with raw pistachios. Bake at 160°C/325°F for 20-25 minutes until golden brown. Cool completely.
09 -
Whisk chilled pistachio cream to loosen it and transfer to a piping bag with a large round tip. Pipe cream over cooled sponge and smooth with an offset spatula. For a spiral pattern, place tart on a turntable and drag spatula from center outward while rotating.
10 -
Sprinkle chopped pistachios around the edges of the tart. If desired, finish with a light dusting of lime zest for a fresh accent.