Directions

1. First make the pastry. Either by hand or using a food mixer with a beater attachment, cream the butter, icing sugar, egg yolks, vanilla and lemon zest together. Add the milk and combine well. Tip in the flour and a pinch of salt, then rub or beat to form a dough. Shape into a thick disc and chill for at least 30 mins or overnight.
2. Meanwhile, make the lemon filling. Beat the eggs and sugar together then add the zest and juice and stir in the double cream. Cover and put to one side.
3. Heat oven to 180C/160C fan/gas 4. Roll pastry out to a little thicker than a PS1 coin and line a 23cm tart tin. Leave the excess pastry around the edges as this can be cut off when the tart has been cooked. Line the tart case with greaseproof paper, fill with baking beans and bake for 20 mins. Remove the baking beans and reduce the heat to 160C/140C fan/gas 3 and cook for another 20 mins. Remove from the oven and allow to cool. Trim off the excess pastry from the edge of the tart using a serrated knife.
4. Pour the lemon mix into the tart case. This may be easier with the tart case sitting in an open oven as so not to have to move it when full of mixture. Turn the oven to 140C/120C fan/gas 1 and cook for 30-35 mins until set with a slight wobble in the centre. Remove and cool to room temperature.
5. For the meringue, put the sugar, 65ml of water and the glucose in a heavy bottomed pan on a medium heat and stir to dissolve the sugar. Once it is dissolved, bring to the boil and use a sugar thermometer to keep an eye on the temperature.
6. Using a pastry brush dipped into cold water, brush down the inside of the pan just above the level of the sugar syrup, this will stop the sugar crystallising. Place the egg whites into a food mixer with a whisk attachment and when the syrup temp reaches 110C, turn on the mixer and whisk the whites
7. When the temperature reaches 118C (soft ball - this will be marked on the sugar thermometer), steadily pour the sugar syrup in a thin stream into the now stiff egg whites and continue whisking for 20 mins until completely cold. Transfer into a piping bag with a medium-size star nozzle. As it is cooked, this meringue can be made in advance. You can even make it the day before.
8. You can pipe the meringue onto the tart as a whole or in individual portions, then glaze with a blowtorch. It can be easier and neater to cut the slices before piping with meringue. They can still be served in tart formation on a serving dish, with an ice-cold glass of limoncello, if you like.