Place the dried fruits in a small bowl with the tea bag and cover with 100ml boiling water. Cover and leave to soak overnight. The following day, squeeze out the teabag and discard.
Line a 900g loaf tin or terrine with a double thickness of cling film so that it overlaps the edges enough to fold back over the top.
Melt the chocolate either in the microwave or over a saucepan of simmering water. Whisk together the sugar, egg yolks and cocoa powder then fold in the yoghurt, melted chocolate and finally the macerated fruit together with the liquid. Whisk the egg whites until soft peaks form and fold through the chocolate mixture. Transfer to the tin, level the surface and freeze overnight. Serve, cut in slices, with a few berries to decorate.