Cut mango into little pieces and remove seeds from guava. Put the fruits in a pan with orange juice.
Add a small piece of star anise and 2 cloves, rum and simmer on very low heat for 10 minutes. Stir occasionally to ensure that the bottom is not burning.
Leave to cool.
Add some warm water to the tapioca so that all the granules dissolve properly. See note 1.
Pour the tapioca into a pot and add milk, water, sugar, cinnamon, a pinch of salt, and let simmer for 20 minutes.
Let cool for about 10 minutes and in 3 dessert glasses, pour some of the tapioca mixture into the glasses. Fill the glasses about ⅓ way full.
Gently, add the fruit mixture on top of the tapioca in the glasses.
Pour the rest of the tapioca on top to cover the fruit mixture.
Cover with cling film and chill before serving.