330g/11oz good-quality dark chocolate (min 64 per cent cocoa solids), in pieces
8 eggs, separated
100g/31/2oz caster sugar
Pinch of sea salt
Prepare the quinces as per the first recipe (see related links).
Melt the chocolate slowly in a heatproof bowl set over a pan of gently simmering water, then remove from the heat and leave to cool slightly.
Meanwhile, beat the egg yolks and half the sugar together in a bowl until pale and thick. Slowly incorporate the melted chocolate.
In a clean bowl, whisk the egg whites with the salt until soft peaks form, then gradually whisk in the remaining sugar.
Carefully fold the egg whites into the chocolate mixture, a third at a time, until evenly combined.
Pour into a large bowl, cover and place in the fridge to set.
To serve, spoon the chocolate mousse on to plates and serve with the roasted quinces.