Grease the tart tin with butter.
To make the pastry sift the flour and salt into a large mixing bowl or food processor bowl.
Add the butter and lard and rub in (or process if using a food processor) until the mixture resembles fine breadcrumbs.
Place the egg yolks in a cup and add the ice cold water and whisk together.
Add to the pastry mix and bring together to make a dough adding more water if the dough is too dry. If using a processor add the egg mixture and whizz until the mixture forms a ball of dough.
Wrap in clingfilm and place in the fridge for half an hour.
Preheat the oven to 160C/320F/gas 2.5.
Remove the pastry from the fridge and leave to come to room temperature – at least half an hour.
Meanwhile, make the filling.
Place 300ml water in the saucepan and bring to the boil. Place the leaves in the saucepan and heat until all the leaves have wilted. You will need to do this in batches.
Drain through a colander and rinse with cold water. Press down to extract as much liquid as you can.
Place the drained leaves on a chopping board and chop with a sharp knife. Hold handfuls of the chopped leaves in between your hands and squeeze any excess water into the sink. Place the chopped leaves in a large mixing bowl along with the parsley and use your hands to disperse them evenly.
Melt a couple of knobs of butter in the frying pan and once it starts to foam add the onions. Sauté on a moderate heat until transparent and starting to take on colour. Add to the leaf mixture.
Add the raisins, parmesan, feta, seasoning, nutmeg and caster sugar and mix through thoroughly.
Beat the eggs in the small bowl and add to the leaf mixture. Mix very thoroughly. Set aside to cool.
Once the pastry has reached room temperature, unwrap it and place on a lightly floured work surface.
Roll out two thirds of the pastry and line the tart tin with it.
Fill with the leaf mixture.
Dampen the top edges of the pie base with a little water or milk.
Roll out the other third of the pastry and place over the filling, crimping the edges to seal.
Cut out decorative shapes from any scraps of pastry and stick onto the top of the pie with beaten egg. A Tudor rose placed in the centre is very appropriate? Make a hole in the centre of the pie top to allow any steam to escape while baking.
Place the pie in the fridge for half an hour.
Remove from the fridge and brush the top with beaten egg and place in the preheated oven for an hour.
Serve either hot or cold.
