Cut rhubarb into thin pieces, boil with 80 g sugar, vanilla sugar, cook for 20 minutes.
Soak gelatine, add dripping wet, crush, put aside to cool. Whip 2 egg whites with 120 g sugar until stiff, whip cream until stiff. Fold in both, when the rhubarb starts to gelatinize, refrigerate, serve with mango slices.