Preheat the oven to 200C/390F (180C/355F fan). Tip the sifted flour, icing sugar and butter into a food processor and blitz until the mix resembles very fine breadcrumbs.
Add the egg yolks and blitz again.
Roll into a smooth ball of dough.
Cut the dough into four equal pieces and roll into four balls.
Flour and flatten each ball, then use a rolling pin to roll each one into 15cm discs, just wide enough to line your tins.
Press each disc carefully into four 10cm loose bottom tart tins.
Fill each tin with a little baking paper and a handful of baking beans or uncooked rice.
Bake for 8 minutes, then remove the paper and beans and return to the oven for a further 5 minutes until a pale golden colour. Check that the bottoms are cooked through.
Leave to cool completely, then trim the edges with a sharp knife before removing the pastry cases from the tins.
To make the filling
Whip the yogurt together with the sugar and vanilla until light and airy. It’s best to use an electric whisk.
To make the glaze
In a saucepan, mix the arrowroot with the lemon juice, sugar and water.
Turn on to a medium heat and gradually bring to the boil, stirring until the mixture is clear and has thickened considerably. Set aside until cool.
To bring it all together
Spoon the yogurt into the four pastry cases so that they are filled to about 1 cm shy of the top.
Arrange the fruit in the cases.
Drizzle with the cooled glaze and finish with a sprig of mint. Serve immediately.