Preheat the oven to 180C/350F/gas 4.
Grease the tart tin with butter.
To make the pastry sift the flour and salt into the large mixing bowl or food processor bowl.
Add the butter and rub in (or process if using food processor) until the mixture resembles fine breadcrumbs.
Place the egg yolk 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 the dough in clingfilm and place in the fridge for 30 minutes.
Remove the pastry from the fridge and cut 150g from the main ball, cover with clingfilm and return to the fridge – this is for the lattice top.
Roll the rest of the pastry out on a lightly floured work surface and line the prepared tart tin.
Prick the base with a fork and place in the fridge to chill for 30 minutes.
To make the filling, place the golden syrup in the saucepan and heat until runny.
Remove from the heat and add the breadcrumbs, lemon juice and zest. Stir thoroughly and pour into the lined tart tin.
Take the reserved pastry from the fridge and roll out.
Cut long strips, 1.5cm wide and as you place them on the tart, twist them. You need to weave the strips which is somewhat fiddly. Leave the strips hanging over the edge so you can raise them when weaving the strips.
Once you have done this you can crimp and trim the edges.
Place in the preheated oven and bake for 40-45 minutes until the pastry is golden brown and the filling set. If, after 20 minutes the tart is browning too much, place a piece of kitchen foil over the top.
Remove the tart from the oven and leave to firm up in the tin.
Take the tart out of the tin and transfer to a serving plate.
Serve warm or cold.
