Place pastry sheet on a lightly floured surface and roll to a thickness of 2mm. Cut 12 pastry rounds using a 12cm round cutter and gently push each round into the muffin tins. Cover with plastic wrap and chill in fridge until required.
Place egg yolks, sugar, cornflour, milk and rind together in a small saucepan over a medium-low heat, stirring continuously until sugar dissolves and the mixture reaches boiling point, thickens and becomes smooth.
Remove from heat immediately, discarding the rind. Stir in the cream and vanilla extract, mixing until smooth and well combined.
Evenly divide the fruit mince amongst the 12 tart cases. Evenly divide the custard over the top, until each pastry case is two thirds full.
Bake tarts in preheated oven for 20 to 25 minutes or until the pastry is golden and the custard has coloured speckles across the surface. Allow tarts to cool on a wire rack. Keep in an airtight container and consume within 2-3 days.