Firstly place a small jug of water into the fridge for use later. When you are making pastry the best results are achieved when all of your ingredients and utensils are kept cold, this includes your hands. Dipping your hands into ice water before making the pastry will make a better pastry.
Sieve the flour into a large mixing bowl. Dice the butter into small cubes and add to the flour. Using your finger tips rub the flour through the flour until a sandy a damp sandy texture is achieved.
Now mix the egg with the sugar and a small dash of water and pour into the flour mix cutting the mixture together using a cold knife.
When the mix is starting to come together, set aside the knife and force it together by hand. Cover the pastry well and leave to rest in the fridge for at least 20 minutes but if you can leave it longer it is better.
Grease and flour a 9 inch dish. Roll out the pastry using as little flour as possible. Allow the pastry to fall over the edge of the dish ensuring it is pushed into the edges. (Do not cut the pastry until you have blind baked it. This will ensure an even crust.) Allow this to rest in the fridge once more for about 10 minutes.
Cover the pastry with parchment paper and pour in some dry rice; this will stop the pastry from rising while baking. Place in a pre heated oven about 180 for 10 -15 minutes or until the pastry just begins to turn golden.
Remove from the oven and cut the excess edge with a sharp knife, allow cooling slightly before adding the lemon mix.
Grate the zest from 3 of the lemons into a round bottom bowl that is capable of with standing heat, ie stainless steal or toughened glass.
Add the lemon juice from all of the lemons or at least 275 ml of juice.
Add the eggs and sugar. Over a pot of boiling water, whisk the mix continuously over the water until it becomes thick and rib boned, remove from the heat and add the diced butter, return to the heat and continue whisking until all the butter has been absorbed.
While the filling is still warm, pour into the tart shell and place in a fridge to cool for an hour or two.
Use a warm damp knife to achieve nice clean slices from the tart.
Before serving, dust with a little caster sugar and glaze with a blow torch.
If you don’t have a blow torch you can simply dust with a little icing sugar.
Either way this tart is best served with a raspberry sorbet or strawberry ice cream. Enjoy.