- Preheat oven to 200°C/400°F/Gas 6. Lightly grease a 20cms/8" flan ring or dish.
- Make pastry: Sieve the flour and icing sugar together. Mix the egg yolk, water and lemon juice together. Place one third of the flour mixture in a bowl, add the margarine and the liquids. Cream with a fork until well blended. Add the remaining flour and sugar mixture and mix to a firm dough. Cover and refrigerate for about 1 hour.
- Roll out pastry on a little flour and use to line the flan ring or dish. Prick the base well with a fork, then, cover with well crumpled tin foil. This prevents the pastry rising during baking! Bake in pre heated oven for 20 minutes until set, remove the tinfoil for the last 5 minutes baking. Remove from oven. Reduce oven to 150°C/300°F/Gas 2.
- Meanwhile make the filling: Place the cornflour and sugar in a saucepan, gradually whisk in the water. Add the lemon rind and bring to the boil stirring until thick and transparent. Remove from heat and stir in the strained lemon juice. Beat in the egg yolks and pour into the flan case.
- Make the meringue: Beat the egg whites in a clean dry bowl with a pinch of salt until stiff. Beat in the sugar until glossy. Spoon meringue over filling, sprinkle with a little sugar and bake for 25 minutes until golden brown.
Refreshing tangy dessert, can be served hot or cold!