Heston's Lemon Tart

This was made using Heston Blumenthal's recipe, but I had to modify as my tart tin was smaller and I wanted the tart less sweet. Baking this tart was a good learning experience on how to bake a custard filling to just setting condition.

The pastry was tasty, soft and crumbly. The filling just set and no more, smooth, very lemon tangy and not too sweet.

Serves 6-8 (small serves)
24cm tart tin, 2 cm deep

For the pastry
60g icing sugar
3 L egg yolks
300g plain flour
150g unsalted butter
1/2 tsp salt
Zest of 1 lemon

For the filling
Finely grated zest and juice of 3 large lemons
250g double cream
120g white castor sugar
7 XL eggs

To finish and serve
50g unrefined castor sugar

Pastry
Blitz icing sugar and egg yolks in a tall container with a hand blender.
Use a mixer with a paddle attachment to mix flour, butter and salt on low speed until resembles fine cornmeal (about 2-3 minutes approx)
Add lemon zest, egg yolk mixture and mix on low speed until fully combine and a very soft dough has formed. The dough will "unstick" from the surface of mixer at this point. This can happen quite quickly especially on a warm day.
Mould dough into a flat square ad wrap in clingfilm, place in fridge for 1 hour.


Blind baking - Preheat oven to 180C/160C fan force

Roll pastry between 2 sheets of baking paper to 2mm thick, place in freezer for 30 minutes. 

Line the tart tin with pastry, prick the base with fork, then place back in freezer for 10 minutes.
Line pastry case with scrunched baking paper and beans/clean coins/rice on top.
Place in oven, blind bake for 20 minutes.
After 20 minutes, remove paper and contents, and return tart case to oven for further 10 minutes.
Take tart case out of oven to cool a little. Trim the overhanging pastry by running a sharp knife round the top of the tart tin and discard. Leave to cool completely.

When ready to bake filling, preheat oven to 120C/100C fan force.
Place all filling ingredients in a bowl and mix together using a spatula.
Place bowl over saucepan of simmering water and allow to warm up until temperature reaches 62C. At this point, strain the mixture through a fine sieve into a pouring jug. With a spoon, remove bubbles from surface, if any.
Slide the oven rack out a bit, pour the mixture into the warm pastry case inside the oven.
Fill the case to the top, slide the rack carefully back in.
Bake approximately 25 minutes or until temperature of filling reaches 70C.
Allow to cool completely at room temperature.

Just before serving, sprinkle a think layer of sugar on top of tart.
Using a blow torch, gently caramelise the sugar while continuing to sprinkle further sugar on top.

Bon Appetite!