This has been one of my favourite technical challenges to make, as Lemon Tarts (Tarte Au Citrons) are one of my favourite things to eat. It is a great challenge as making the perfect short crust pastry can be difficult, you have to make sure the pastry is chilled enough otherwise the pastry will shrink when it is baked in the oven. Another issue is baking the tart filling because if the oven is too hot or the tart is over baked it can cause the filling to crack on the top of the tart.