To make the base of the tart, pre-heat the oven to 190C
In a bowl, cream butter and organic sugar.
Beat in the egg-yolk
Mix in flour and beat until the dough begins to come together.
Knead the dough and divide into two equal halves. Wrap them with plastic wrap individually and chill in the fridge for 15 minutes or until the dough is firm.
Roll out the dough and line the tart tins with the rolled out dough. Chill in the freezer for another 15 minutes