It is rare to see crème mousseline these days unless you visit very fine patisseries. It is also called German buttercream and is essentially a crème pâtissière enriched with a whole lot of butter – incredibly decadent! It’s good to have lots of different filling alternatives so you can really experiment with the look and feel of your beautiful baked goods.
Remove the chocolate puff pastry from the fridge and set aside.
To make the pecan praline, line a large baking sheet with baking parchment and spray a little oil on it, then set it aside. Put the sugar and water into a pan over a low heat and allow the sugar to dissolve. Have a pastry brush standing in a cup of hot water nearby and use this to brush down any sugar on the sides of the pan, as it may cause the mixture to crystallize into a lump.
Once the sugar has dissolved, turn up the heat and allow the mixture to boil. Keep it bubbling away for about 6 minutes, or until the mixture turns to the colour of honeycomb – not too dark as it will taste bitter. Once it is ready, take it off the heat. As soon as the bubbles have subsided a little, add the pecans, moving the pan around gently to swirl the mixture a little. Make sure all of the pecans are covered and then pour the mixture onto the lined baking sheet and set aside to cool down.
Once the mixture is cool and hard, pop it into a food processor and blitz, then set this aside. You don’t want massive pieces but you don’t want it to be blitzed into a powder either, so aim for small bite-sized chunks.
Line a large baking sheet with baking parchment. Roll out the chocolate puff pastry on a lightly floured surface until it is slightly thinner than a £1 coin (about 3mm). Then using the 9cm round cutter, stamp out rounds from the pastry, re-rolling if need be to get twelve rounds. Brush off any excess flour and then put six rounds on the baking sheet and set aside. Take the 5cm round cutter and cut out the centres of the remaining six rounds on the floured work surface. You will be using the large rings for this recipe, so set the 5cm cut-out rounds aside.
Brush egg wash around the outside edge of the pastry rounds on the baking sheet, making sure that the egg does not run down the sides as this may stop the vol-au-vents from puffing up nicely in the oven. Place each pastry ring on top of an egg-washed round, to give you six vol-au-vents in total. Brush a little more egg wash all over the tops of the vol-au-vents, again making sure not to drip any down the sides. Pop these into the fridge to firm up for 30 minutes.
As the puff pastry is cooking, make the crème mousseline. Put the egg yolks and caster sugar together in a bowl and whisk together well for a few minutes, until the mixture lightens to a much paler yellow. Once the mixture has reached this stage, add the cornflour and whisk very well again, then set it aside.
Put the milk and the vanilla pod and seeds in a pan over a medium–high heat until just boiling, then remove it from the heat and add one third of the milk to the egg yolk mixture, whisking well. Then add the rest of the milk to the egg yolk mixture and whisk again (you don’t really want to get lots of air into it). Pour this mixture back into the same pan and put it on a medium–high heat, until it starts bubbling. Turn down the heat and cook through, stirring for a good 2–3 minutes to ‘cook out’ the cornflour as it thickens a little. Then put the mixture into the bowl of a stand mixer and beat on quite a low speed until it reaches body temperature. You can also use a hand-held electric whisk for this. Add the butter, bit by bit, beating well between each addition. Once all of the butter is added, tip in three-quarters of the praline and stir to combine.
Once the vol-au-vents are baked, remove them from the oven and sprinkle the tops with some icing sugar. Place them briefly under a hot grill for a few seconds, so that the icing sugar caramelizes to a nice sheen. Keep an eye on them as they can burn in super-quick time.
Half-fill the piping bag with praline crème mousseline and then pipe it into the vol-au-vent cases. I like to fill them pretty much up to the top. Put three raspberries on top of each vol-au-vent and then sprinkle over the remaining praline. Serve.
© Lorraine Pascale, 2017. Images: © Myles New, 2017.