3 lemons, juice and zest
175g/6oz plain flour
150²µ/5½´Ç³ú caster sugar
25g/1oz icing sugar
icing sugar, for dusting
100g/3½oz plain chocolate (36% cocoa solids), chopped
100g/3½oz cold butter, cut into small cubes
100ml/3½fl oz double cream
4 large free-range eggs
1 free-range egg yolk