Line 4 small pudding-shaped moulds (200ml capacity) with cling film, smoothing it over to fit snugly, leaving an overhang around the edge. Finely grate the zest from the clementine and put it to one side. Squeeze 3 tbsp of juice and put it in a pan with the rum and sugar.
Heat gently until the sugar has dissolved. Tip in the cranberries and raisins, and simmer for 2 mins (no more or it will become too thick) to plump up the fruit.
Pour into a bowl, stir in the mixed peel and clementine zest, and leave until cold (about 1 hrs, or you can leave overnight).
In a medium bowl, beat the yogurt with a spoon until smooth. Whip the cream so it's softly whipped, then fold into the yogurt. Measure off 4 tbsp of the fruit and its syrup, and set aside in a rigid freezer container (freeze for up to a month). Stir the rest into the yogurt mixture.
Pour or spoon the mixture into the pudding moulds. Bring the overhang of cling film over the puddings, then cover with foil. Freeze for up to a month.
For the chocolate stars, cover a baking sheet with baking parchment. Draw 4 star shapes on the paper with a pencil (no need to be too accurate), then turn the paper over. Melt the white chocolate and, using a teaspoon, drizzle 4 star shapes over the pencil outlines. Leave to harden. Freeze the chocolate stars in a rigid freezer container layered between greaseproof paper.
When ready to use, thaw the extra fruit and syrup at room temperature and the puddings in the fridge for 1 hr. Tip the puddings onto plates and peel off the lining.
Serve with some of the sauce spooned over, with a chocolate star propped up against each one (the stars can be used straight from the freezer).
