Measure the juice and make up to 275 ml
with water.
Put the rind, juice and honey into a
small bowl, sprinkle on the gelatine, place over a pan of hot water
until the honey has melted and the gelatine dissolved.
Leave to cool.
Whisk in the yoghurt and leave until
the mixture is on the point of setting.
Fold in beaten egg whites.
Spoon a little of the mousse into 4
individual serving glasses, sprinkle with the muesli and continue making
layers, finishing with a topping of muesli.