Fold the cream into the yogurt and chill for 30 minutes.
Put 250g/9oz strawberries in a blender or food processor, blend to a purée, then stir in the crème de cassis. Measure out 75ml/3fl oz of the purée and reserve.
Slice the remaining strawberries into a bowl, reserving 6 for decoration, then pour the purée over and chill in the bowl for 20 minutes.
Break up the meringue nests, and carefully fold into the cream mixture along with the strawberry mixture. Divide between six serving glasses, then drizzle over the reserved purée.
Decorate with the reserved strawberries, and serve.