Sift flour into a large mixing bowl. Then cut the butter and lard into small cubes and add to the flour. Using your fingertips, lightly rub the pieces of butter and lard into the flour until it resembles breadcrumbs.
Add cold water and using a knife mix, adding more water as needed.
Then bring the mixture together with your hands to form a smooth ball or pastry dough. Wrap in cling film and put into the fridge for 30 minutes.
Grease an 8 inch pie dish. Roll out pastry to a round and place the dish over the pastry to make sure it’s large enough. Line the pie dish with pastry and allow to rest for 20 mins.
Pre-heat the oven to 180oC and baking tray. Prick base of the pastry with a fork and place a sheet of tin foil on top and fill with dry beans or rice.
Place on preheated try and bake blind for 20/30 minutes until cooked through. Remove from oven and lower the temperature to 150°C.
For Lemon Filling
Measure water into a jug. In a bowl add cornflour and sugar and add enough water to mix the cornflour to a smooth paste. Then, in a small saucepan add the remaining water, and the grated lemon rind. Bring to the boil.
Pour it onto the cornflour paste and mix until smooth. Transfer the mixture back to the saucepan and return to the boil. Then reduce the heat and simmer for 1 minute stirring constantly.
Remove from the heat and beat in the egg yolks, lemon juice and butter.
Pour the lemon filling into the baked pastry case and spread it evenly
In a clean dry bowl, whisk the egg whites and salt until they form stiff peaks. Add the sugar, a spoonful at a time until it is all incorporated
Spread the meringue mixture all over the filling.
Cook for 30 minutes at 150°C. Serve straight from the oven, or, my favourite way is to let it go cold with a generous dollop of whipped cream.