Recipe

1. Preheat the oven to 425°F/220°C/200°C Fan/Gas 7. Line the baking sheet with parchment paper.
2. To make the sponge base, place the egg whites and half the sugar in a bowl and beat with an electric whisk until fluffy and frothy, and the sugar has dissolved. Beat the egg yolks with the remaining sugar and a tablespoonful of water, until light and frothy. Add one-quarter of the egg whites to the yolk mixture. In a separate bowl, combine the flour with the pistachios chopped with sugar, then fold it into the yolk mixture with a silicone spatula. Fold in the remaining egg whites. Pour the mixture into the prepared baking sheet and bake in the preheated oven for 10 minutes, until golden and firm to the touch — a skewer inserted into the center should come out clean. Leave to cool, then cut 6 disks out of the sponge with the pastry cutter.
3. To make the mousse, soak the gelatin in cold water for 5 minutes. Hull the strawberries, then puree them in a food processor. Transfer to a saucepan and add the sugar. Strain the lemon juice and add to the pan along with the vanilla bean (pod), cut lengthwise. Cook over low heat for 5 minutes, or until the sugar has dissolved, then remove the vanilla bean. Squeeze the water from the gelatin, add to the saucepan, and stir until dissolved. Pour through a fine-mesh strainer (sieve) into a bowl and leave to cool, stirring occasionally. Whip the cream to soft peaks and the whisk in the strawberry puree. Pour the mixture into the silicone molds. Place the molds in the refrigerator and leave to set overnight.
4. To make the glaze, soak the gelatin in cold water for 5 minutes. Hull the strawberries and puree in a food processor, then transfer to a saucepan and add the sugar. Squeeze the water from the gelatin, add to the pan, place on very low heat and cook for 2 to 3 minutes, stirring continuously until the gelatin and sugar have dissolved — do not let the puree boil. Pour through a fine-mesh strainer into a bowl and leave to cool to room temperature, stirring occasionally.
5. Once set, remove the mousses from the molds and place them on a cooling rack. Pour over the glaze and transfer to the refrigerator for 30 minutes to set. To serve, place the pastry bases on a serving plate, sit the mousses on top, and scatter over the pistachios.

Mistakes To Avoid

As the fruit puree cools, stirring the mixture stops it setting too quickly. If set rapidly, a skin can form leaving streaks in the mousse.

Tips & Tricks

If you do not have a silicone mold then brush the insides of a metal mold with a little flavorless vegetable oil before using. Then, when unmolding the mousse, dip the mold in hot water for 10 seconds.