Put the rice on a sieve and wash under cold running water. Cut the vanilla pod lengthwise and scrape out the pulp. Bring the milk, rice, sugar, lemon zest, salt, vanilla pod and pulp to the boil and allow to swell at low heat for 20-30 minutes.
Stir occasionally. In the meantime, wash the grapes, dab dry and pluck them from the stalks. Halve or quarter the grapes and remove the seeds. Roast almonds in a pan without fat, remove and let them cool down.
Let the rice pudding cool down as well. Remove the vanilla pod and lemon peel. Whip the cream until stiff and fold into the cold rice pudding. Fold in half of the grapes as well and distribute on glass plates.
Sprinkle with remaining grapes and almonds. Serve decorated with a small grape, if desired.