01 - Melt 5.3 oz chopped dark chocolate in a heatproof bowl set over a pan of simmering water using a double boiler technique. Stir until smooth, then remove from heat and allow to cool slightly.
02 - In a clean bowl, whisk egg yolks with 0.7 oz sugar until the mixture becomes pale and creamy. Gradually incorporate the cooled melted chocolate, stirring until fully combined.
03 - In a separate bowl, beat egg whites with salt until soft peaks form. Gradually add the remaining 0.7 oz sugar while continuing to beat until stiff peaks form.
04 - Gently fold the whipped egg whites into the chocolate mixture in three batches, using careful folding motions to preserve the airiness and avoid deflating the mixture.
05 - In another bowl, whip 6.8 fl oz chilled heavy cream to soft peaks. Fold gently into the chocolate mixture until just combined, maintaining the light texture.
06 - Divide the mousse evenly among 4 serving glasses or bowls. Refrigerate for at least 2 hours until fully set.
07 - Whip 3.4 fl oz chilled heavy cream with powdered sugar until soft peaks form.
08 - Top each mousse with a dollop of whipped cream. Using a vegetable peeler, create chocolate curls from 0.7 oz chocolate and sprinkle over the whipped cream. Serve immediately while chilled.