Preheat the oven to 180'C.
For the base:
Sift the flour and the icing sugar into a food processor bowl. Add a pinch of salt. Cut the butter into small cubes and add to the dry ingredients. Pulse the mixture until you have a breadcrumb consistency. Add the egg yolks and pulse again until the mixture comes together as a ball. Be careful not to overwork the pastry.
Roll out the pastry base to 3mm thick and line individual tart tins with the pastry. Prick the base of the tarts lightly with a fork and place in the fridge to firm up for a short while. Blind bake the cases in the oven for 18 minutes.
To blind bake: put a layer of parchment paper on top of the lined tart cases and cover with baking beans.
Whilst the bases are cooking, make the lemon and orange filling:
Zest and juice the oranges and lemons. Whisk this into the eggs, sugar and double cream.
Remove the pastry base from the oven and pour in the cream.
Reduce the oven temperature to 140c, return to the oven and cook for 10 minutes.
Serve cold with a drizzle of cream and a dusting of icing sugar.
«To make a lemon tart simply replace the orange with extra lemon juice and zest. You may also have to add a little extra sugar to the cream to balance the tartness of the lemons.»