Use the best couverture white chocolate you can find, such as
Lindt or Valrhona.
325 mlpouring cream1titanium-strength gelatine leaf, softened in cold water for 5 minutes150 gmwhite couverture chocolate, finely chopped, plus extra shavings to serve125 gmcrème fraîcheTo serve:white nectarines or peaches, sliced into thin wedgesPassionfruit syrup10passionfruit100 gmcaster sugar
Bring 150ml cream to the simmer in a saucepan over medium heat, squeeze excess moisture from gelatine and add to cream, stirring to dissolve. Place chocolate in a bowl, pour hot cream over and stir occasionally until chocolate melts (5-10 minutes), then cool, stirring occasionally until thickened but not set. Meanwhile, whisk remaining cream and crème fraîche to soft peaks, fold through chocolate mixture, transfer to six 250ml glasses and refrigerate until set (1 hour).
For passionfruit syrup, process passionfruit pulp in a food processor, then strain to produce 75ml juice. Bring sugar and 150ml water to the simmer in a saucepan, stirring to dissolve sugar. Add passionfruit juice and remove from heat. Cool, then strain through a fine sieve lined with muslin. Refrigerate until required.
Top mousse with nectarine or peach slices and white chocolate shavings and serve with syrup to taste.