In a large bowl beat the eggs and sugar, then combine the lemon and lime juice, yoghurt, and condensed milk. Set aside until ready to use.
Line the shortcrust pastry onto a 20cm (3.5cm H) fluted tart tin, cut off excess. Let it rest in the refrigerator for 10-15 minutes.
Place a piece of baking paper into the tin and fill with baking weight. Blind bake the tart case in the oven for 15 minutes, then remove the baking paper and weights and bake for a further 15 minutes or until the pastry is golden. Remove from the oven, then turn down the oven temperature to 140C.
Pour the lemon lime egg mix into the tart case and bake for 30-40 minutes or until set. Let the tart cool before removing from the pastry case.