Soak the gelatine in cold water according to the instructions on the package. Squeeze out the gelatine well, warm up some orange juice in a saucepan and dissolve the gelatine in it. Gradually add the remaining orange juice and stir well.
Beat the egg yolks with the sugar until frothy. Add to the orange juice with the lemon juice and lemon zest, stir well and keep in a cool place until the mixture starts to gel.
Whip the cream and egg white separately and fold in carefully.
Put in a suitable form or serving glasses and put in a cool place for at least 2 hours.
Tip:
Line a heart shape with cling film and fill with the mousse. Then carefully turn the mousse out onto a plate. Garnish with fresh orange slices, chopped pistachios and whipped cream.