For the pastry
175g/6oz plain flour
100g/3½oz cold butter, cut into small cubes
25g/1oz icing sugar
1 free-range egg yolk
1 tbsp cold water
For the first layer
5 free-range eggs
125ml/4fl oz double cream
225g/8oz caster sugar
4 lemons, juice and zest
icing sugar, for dusting
For the second layer
3 x 61 g free range eggs
100 g castor sugar
2 gelatine leaves
¼ cup hot water
300 ml rich cream (45% fat)
To make the pastry, place the flour, butter and icing sugar into a food
processor. Pulse briefly until the mixture resembles breadcrumbs,
then add the egg yolk and water.
Pulse again until the mixture sticks together in clumps then tip onto a
work surface and gather it into a ball with your hands. Knead the
pastry just two or three times to make it smooth. If your butter was a
bit too soft, the pastry might be too. If so, wrap it in parchment paper
and chill for 15 minutes.
Grease a 23cm/9in loose-bottomed, fluted tart tin.
Lay a piece of parchment paper on the work surface. Remove the
base from the tart tin and lay it on the paper. Using a pencil, draw a
circle onto the paper 4cm/1½in bigger than the tin base.
Dust the base of the tin with flour. Place the pastry ball in the centre
of the tin base and flatten it out slightly. Roll out the pastry, still on
the base, until it meets the circle mark. As you are rolling out, turn
the pastry by turning the paper. Gently fold the pastry surrounding
the tin base in towards the centre.
Carefully lift the tin base off the work surface, drop it into the tin, then
ease the pastry into the corners and up the sides of the tin, pressing
the overhang lightly over the rim. If the pastry has cracked at all,
simply press it together to seal. Press the pastry into the flutes of the
tin then lightly prick the base with a fork, but not quite all the way
through. Place the pastry-lined tin on a baking tray, cover loosely
with cling film and chill in the fridge for 30 minutes. Preheat the oven
to 200C/400F/Gas 6.
Remove the cling film from the pastry case and line with foil so it supports the sides,
then fill with baking beans.
Bake blind for 12-15 minutes, until the pastry is set, then lift out the foil and beans.
Carefully trim the excess pastry from the sides using a sharp knife,
holding the knife at a sharp angle and slicing away from you.
Remove the trimmings from the sheet. Return the empty pastry case
to the oven for another 10-12 minutes or until it is pale golden and
completely dry. Set aside to cool while you make the filling. Reduce
the oven temperature to 170C/325F/Gas 3.
For the base filling
Break the eggs into a large bowl and whisk together
with a wire whisk. Add the rest of the filling ingredients and whisk
again until they are all well combined. Pour the filling mixture into a
jug, then into the cooled baked pastry case. To prevent it spilling as it
goes in the oven, pour in most of the filling so it almost fills the tart,
carefully sit the baking sheet and tart on the oven shelf, then top up
with the rest of the filling to completely fill it. Bake for about 30-35
minutes or until just set but with a slight wobble in the centre.
Leave to cool slightly then, when the pastry seems firm enough,
remove the tart from the tin. The easiest way to do this is to place the
base of the tin on an upturned can or jam jar and let the outer ring fall
to the work surface. Allow to cool completely.
For the second layer
Separate the eggs. Finely grate the zest of lemons and then juice them (you’ll need 100 ml strained juice). Bring a large saucepan of water to the boil. Put the egg yolks, zest, juice and castor sugar into a large stainless steel bowl and set this over the boiling water, then whisk until pale and thick. Remove the bowl and set aside.
Soften the gelatine in a little cold water for 5 minutes, then squeeze out any excess moisture and dissolve the leaves in the hot water. Whisk this into the egg mixture and refrigerate until cold and just starting to set.
Whish the cream until soft peaks form, then fold this through the cold sabayon. Refrigerate until just starting to set. Whisk the egg whites until soft peaks form (be careful not to over whip them or the texture of the final dessert will be crumble rather than soft and light) and fold these through too.
Spoon the mixture into the cooled tart and allow to set in the fridge for about 3 hours.