- 100g/4oz icing sugar, plus extra for dusting
- 250g/9oz ready-made puff pastry, thawed if frozen
- 200g/7oz, or 1 punnet, blueberries
For the cream filling
- 165g/5½oz whipping cream
- 25g/1oz icing sugar
- Seeds of 1 vanilla pod or 2 drops vanilla extract
- Finely grated zest of 1 lemon and a squeeze of juice
For the hot chocolate sauce
- 165ml/5½oz double cream
- 100g/4oz good milk chocolate or dark chocolate (or a mix of both), finely chopped or grated
- 25g/1oz butter
- 1 generous tbsp golden syrup
Line a large baking tray with nonstick baking paper. Dust the work surface with lots of icing sugar and roll out the pastry to a rectangle just larger than 27 x 30cm/10½ x 12in (the pastry should be super thin, as thin as you can get it). Cut the edges straight, then cut out 18 rectangles about 9cm x 5cm/ 3½in x 2in, and place them on the baking tray. Sprinkle with lots of icing sugar and chill in the fridge for 30 minutes.
Meanwhile, preheat the oven to 200°C, 400°F, Gas 6.
Remove the pastry from the fridge and bake in the preheated oven for 5 minutes, then remove and sprinkle the rectangles with more icing sugar. Return to the oven and bake for a further 5 minutes, or until the pastry turns a golden brown. Remove from the oven and set aside.
For the filling, whip the cream, icing sugar and vanilla seeds or extract in a bowl until medium-stiff peaks form. Fold in the lemon zest and juice to taste, then fill a piping bag fitted with a 1cm/½in straight nozzle with the mixture.
To make the chocolate sauce, heat the cream in a pan until just boiling, then remove from the heat. Add the chocolate and butter and leave to stand, without stirring, for 5 minutes, then stir until everything looks smooth and uniform. Add the golden syrup and stir a couple of times. Set aside.
Place a pastry thin on a serving plate. Pipe blobs of cream on the top, then place some blueberries between the blobs. Settle another pastry thin on top and repeat with another layer of cream and blueberries. Top with a third pastry thin and sprinkle with more icing sugar. Continue until you have made 6 millefeuilles.
Serve with the hot chocolate sauce poured all over.