Bring 250 ml milk, rice, lemon peel, salt, sugar and raisins to the boil. Leave to swell on low heat for 35 minutes, stirring from time to time. Pour the remaining cold milk into a large bowl.
Add the chocolate sauce powder and immediately whisk vigorously through with a whisk for about 1 minute. Peel the orange so that the white skin is completely removed. Cut out the fillets between the parting skins.
Arrange rice pudding and orange filets in a deep plate. Decorate with lemon balm. Add chocolate sauce extra.