Grate the zest and squeeze the juice from the clementines and lemons.
Put the orange jelly powder in a medium bowl and add 300ml boiling water. Stir in the fruit juice and zest, then leave to cool.
Pour the cream into the cooled fruit mixture and chill for 10-15 minutes until just beginning to set.
Whisk the egg white to soft peaks, add the sugar and whisk until stiff. Fold into the cream mixture and divide between four individual serving dishes.
Chill for 1 hour until set.
Make sure the bowl and whisk are spotlessly clean. Any residue of fat will prevent the egg white from whisking up properly.
