Separately soak 5 gelatine sheets in cold water. Squeeze oranges. Mix 300 ml juice, 150 g yoghurt and 3 tablespoons sugar. Squeeze 5 sheets of gelatine, dissolve at low heat. Stir in a little cream, then stir into the rest of the cream
Squeeze the grapefruit, mix 300 ml juice, 150 g yoghurt and 3 tbsp. sugar. Squeeze 5 sheets of gelatine, dissolve over low heat. Stir in a little cream, then stir into the rest of the cream. Put creams in a cool place until they start to gel
Whip the cream until stiff. Fold half into the creams. Pour into 4 cold rinsed moulds (each containing approx. 150 ml) one after the other. Chill for at least 4 hours.
Boil up the rest of the juice and 1 tablespoon of sugar. Stir starch and 1 tablespoon of water until smooth. Bind juice with it. Let cool down. Turn out cream and serve with sauce. Decorate