For the pastry, place the flour in a mixing bowl and make a small hole in the center. Beat in the eggs, lemon zest and sugar, then add the extra-virgin olive oil, salt and bring together with a wooden spoon into a dough. Alternatively place the ingredients -following the same order- into a electric mixer, and mix the dough for about 2-3 min or until comes together.
Transfer the dough to a work surface and continue to work with your hands until you have a smooth even dough. Flatten into a thick disc, cover with cling film and chill for 30 min.
In the meantime, finely slice the nectarines and arrange on parchment paper, covered with a dump towel, until ready to use.
Preheat oven to a 180C/360F and keep the oven rack adjusted to the middle position.
Remove the pastry from the fridge, and roll it out to a ½-inch thickness on a lightly floured surface.
Line the tart pan with the pastry, pressing well into the edges. Slice off the pastry in excess, and prick the base all over with a fork. Place in the freezer for 5-10 min.
Remove the tart crust from the freezer, and brush the base all over with apricot jam.
To fill the tart, put one nectarine slice, skin-side up,against the edge of the pastry. Put the next piece beside, slightly overlapping it, and continue around the edge of the tart to complete a circle. Repeat in rings, until you rech the centre.
Brush the nectarine slices with extra apricot jam and place your tart in the oven.
Bake for 20-30 min, or until the edges are golden-brown and the base is baked through.
Remove from the oven and allow to cool. Decorate with confectioner sugar and serve.
Store in an air-tight container in the fridge for up to 3 days.