SWEET DOUGH

1. Place the butter in the bowl of a stand mixer fitted with the paddle attachment. Work the butter on low speed until smooth and the same texture throughout.
2. Add the powdered sugar and mix together on medium speed until combined, taking care not to aerate too much - you don’t want it to be pale and fluffy.
3. In a separate bow., combine the egg yolks and cold water. While still mixing, add to the butter mixture bit by bit. At this stage the mix may look as if it has separated, but once the flour is added this will be rectified.
4. Now turn off the mixer, then tip in the flour and salt. On low speed, work in the flour and salt until the mixture comes together and is crumbly. Do not overwork at this stage, as the gluten in the flour can activate and the pastry could become tough.
5. Tip the contents of the bowl onto a work surface, and using the heel of your hand, smear the mixture away from you until it looks smooth and no patches of butter remain.
6. Using a palette knife or scraper, scrape the pastry together into a mound. Divide the mound of pastry in half and pat each into a round about 1 ¼” (3cm) high. Wrap in plastic wrap and refrigerate until chilled all the way through, 1 hour or overnight.

BLIND BAKING TART SHELL

1. Roll the pastry out on a lightly floured surface, then use to line a 10 inch (26cm) loose bottomed flan tin about 2 inches (4 ½ cm) deep, or a cake ring placed on a baking tray lined with parchment. Leave excess pastry overhanging the edge of the tin - you will trim this off after cooking the pastry. Refrigerate for 25 minutes.
2. Pre-heat the oven to 350°f / 180°c. Line the pastry case with parchment paper, then fill to the top with baking beans or uncooked dried beans or rice. Bake for 18 to 20 minutes, until pale golden. remove from the oven and lift out the paper and beans, then return to the oven and bake for a further 5 minutes. Remove from the oven again, brush the beaten egg yolk over the hot pastry and return to the oven for 5 more minutes. Remove once more and transfer to a rack to cool. Reduce the oven temperature to 225°f / 110°c.

LEMON FILLING

1. Put the lemon juice and the sugar in a saucepan and bring to the boil over a medium heat, stirring occasionally. Remove from the heat, stir in the lemon zest and leave to infuse for 3 to 4 minutes, then pass through a fine mesh sieve.
2. Put the cream in a separate saucepan and bring to the boil over a medium heat, then remove from the heat and allow to cool slightly. Put the eggs and yolks in a large mixing bowl and whisk together. While still whisking, pour the lemon juice/ sugar mixture onto the eggs. When fully incorporated, whisk in the cream and then pass the mixture through a fine sieve. Skim off any bubbles from the top.
3. Place the cooled pastry case, in its tin, on a baking sheet and place this on a shelf in the oven. Gently pour in the lemon filling, taking it to the very top and being very careful to avoid any spillage. Bake for about 40 minutes, until only just set. The middle should wobble like a jelly (jello) when the tart is cooked.
4. Remove from the oven and allow to cool at room temperature on the baking sheet for at least 3 hours - do not put in the fridge or the pastry will go soggy. When cool, neatly trim off the excess pastry from around the edge of the tart using a small paring knife.
5. Carefully remove the tart from the tin or ring, then cut it into wedges. Dust with powdered sugar and caramelise with a blow torch, or finish with Swiss meringue.

SWISS MERINGUE

1. Measure the egg whites and granulated sugar into the bowl of a stand mixer or other heatproof bowl. Place over a pot of simmering water, ensuring that the water does not touch the bottom of the bowl. Heat the mixture, whisking often and watching the edges carefully, until it no longer feels gritty when rubbed between your fingers, and it registers at least 160°f / 70°c on a thermometer.
2. Carefully transfer to a stand mixer fitted with the whisk attachment. Add the vanilla bean paste. Whip on high speed until stiff peaks just start to form - you do not want the meringue to dry out too much or it will not shape nicely. It should be glossy and flow slightly.
3. Dollop the meringue on top of the cooled tart, and swoop into your desired shape using an offset spatula. Torch using a blow torch.