Wash the lemon hot, rub dry and peel the peel thinly. Cut the vanilla pod open lengthwise. Scrape out the pulp with a knife. Bring the milk, lemon zest, vanilla pod and pulp, salt and sugar to the boil.
Add rice while stirring and let it swell at low heat for 30-35 minutes. Stir several times. Drain mandarins on a sieve. Collect the juice. Remove rice pudding from the stove.
Remove the lemon zest and vanilla pod. Stir 6 tablespoons of mandarin juice into the rice pudding. Fold in the fruit. Fill rice pudding into a bowl. Decorate with lemon balm and orange peel spiral.