The definitive recipe is in Marco Pierre White's White Heat. This one reduces
the measures to something more manageable at home.
75g strong white flour
1 tbsp (25g) cornflour
50g unsalted butter, softened
1 egg yolk
2 tsp cold water
For the filling
4 large eggs
200g caster sugar
200ml lemon juice (about 3 large lemons)
Zest of 3 lemons
125g double cream or cr me fra che
Heat the oven to 150C (fan assisted)/300F/gas mark 2. Sift the flours and rub
the butter through evenly. Beat the yolk with the water, add to the bowl and
work to a dough. Wrap and chill for 30 minutes, roll out thinly, then use it to
line an 18cm tart case. Press non-stick parchment against the pastry sides and
bottom, weigh it down with baking beans, bake for 30 minutes, then carefully
remove the paper and bake until the base turns crisp golden brown (pale is a
crime).
Whisk the filling ingredients, leave for 30 minutes, then skim off any froth.
Heat the filling in a pan over a low heat until very warm but not thickened,
stirring constantly with a wooden spoon, then strain into a jug.
Remove the pastry from the oven; use leftover raw pastry to fill any holes or
cracks. Pour in the filling and bake on a tray for 15-20 minutes until barely
set (it will cook as it cools). Serve cold with a dusting of icing sugar.