Method

• 1.
  Start with the pastry shell. Preheat oven to 190°C/170°C fan-forced. Prepare a 23cm loose-based tart pan by lining the bottom with baking paper and greasing sides with butter. If needed (some store-bought pastry may be the perfect size right out of the package), on a lightly floured surface, roll out dough to a circle roughly 3-5mm thick and large enough to line base and side of pan, plus extra to poke above the edge by about 1cm. Carefully line pan with pastry and press it down so it covers the base and side, with excess overhanging.
• 2.
  Cover pastry with baking paper and fill with dried beans or pastry weights. Place pan on a baking tray and bake for 20 minutes, then remove paper and beans. Prick pastry base and sides with a fork about 15 times, then bake for another 10-15 minutes, until golden brown. Set aside to cool.
• 3.
  To poach apricots, add Sauternes, lime half, vanilla, sugar and 2 tbs water to a saucepan just big enough to hold apricot halves in one layer. Place pan over high heat. Cook until sugar has melted and liquid boils.
• 4.
  Remove pan from heat and place apricots in the hot liquid, cut-sides down. Leave them to poach in residual heat until soft but still holding shape (20-40 minutes, depending on ripeness), flipping them every 10 minutes. Transfer apricots to a covered container and refrigerate until needed. Squeeze lime into the syrup, then discard lime. Return pan with syrup to medium-high heat and simmer until reduced and thickened, about 5-8 minutes. Set aside at room temperature until needed (or, if making this recipe over two days, store in a container in the fridge).
• 5.
  Next, make the frangipane. Reserve 1 1/2 tbs pistachios for serving. In a food processor, blitz remaining pistachios until coarsely ground. Add marzipan and blitz to a coarse crumb. Add remaining frangipane ingredients and a large pinch of fine salt. Blitz for 30 seconds, or until just combined.
• 6.
  Once tart shell has cooled completely, trim and discard excess pastry. (If making recipe over two days, wrap pastry in plastic wrap once cooled and store at room temperature.) Spoon frangipane into tart shell. Spread it flat with the back of a spoon. Cut 100g of the apricot halves (3 or 4 halves) into quarters (or sixths if larger) and arrange evenly over frangipane, pushing them down gently. Bake tart for 20-25 minutes, until golden brown and just set. Set aside until cool enough to handle. Remove tart from pan. Set on a wire rack to cool completely.
• 7.
  While the frangipane is baking (or the next day), make the creme patissiere. In a medium bowl, whisk 11/2 tbs sugar with the cornflour, flour and yolks until smooth. Add milk, butter, vanilla and remaining 1 1/2 tbs sugar to a saucepan over medium-high heat and cook until warm but not boiling. Remove milk from heat. While whisking, pour one-third of the warm milk into the egg mixture, and continue to whisk well. Pour the mixture back into the pan with the rest of the milk and return to medium-low heat. Cook, whisking vigorously, until mixture bubbles and becomes very thick. Remove pan from heat and leave to cool for 5 minutes, then spoon over the cooled frangipane, smoothing with the back of a spoon. Cover surface with plastic wrap and chill for 2 hours, or until completely set.
• 8.
  Just before serving, cut remaining apricot halves into quarters (or sixths). Arrange in circles over the creme, cut-side up, leaving 5cm gaps (push them down slightly as you go). Drizzle tart with 1 tbs poaching syrup, then orange blossom water. Roughly chop reserved pistachios and mix with 1 tsp sugar. Sprinkle in gaps between apricots to cover creme, and serve at once, with remaining syrup drizzled over each piece once sliced.