Boil the pearl barley or rice pudding as described on the package.
Drain the can of pineapple and collect the juice. Drain the mandarins as well, the juice from them is not needed.
When the pearl barley is ready, it has to cool down a little. During this time, bring the pineapple juice with the sugar and starch to a boil in a saucepan and let it thicken while stirring constantly.
Cut the marshmallows and pineapple into small cubes and mix with the pearl barley.
Now add the pineapple juice and the drained mandarins.
Mix everything well and let it cool in the refrigerator for 3 - 4 hours.
Before serving, whip the cream until stiff and fold it into the salad, this makes it particularly fresh and fluffy.