For the ketchup, place the vinegar, bay leaf, coriander, cinnamon and sugar into a heavy-based saucepan and bring to a gentle simmer.
Add all of the remaining tomato ketchup ingredients, except the cornflower, and bring to the boil, stirring occasionally to prevent any sticking or burning.
Once boiling, reduce the temperature and simmer, stirring frequently, for 30 minutes. Be careful the mixture doesn't burn or catch on the base of the pan as this will ruin the sauce.
Remove from the heat and allow to cool for a few minutes. Transfer to a food processor and blend until smooth. Push the sauce through a sieve into a bowl and allow to cool completely.
If you find the ketchup is too thin once cold, place into a pan and boil until thickened, stirring frequently. If necessary, add half a teaspoon of cornflour mixed to a paste with water. This will prevent the tomato water separating from the ketchup, but be careful not to make it too starchy and thick.
For the pork, heat the oil in a large saucepan or a deep fat fryer to 190C/375F.
Place the pork fillet between two pieces of cling film then bash with a rolling pin or meat hammer until just 5mm/¼in thick.
Remove the cling film and lay the cheese over one half of the pork then lay the ham on top of it. Flip the other side of the pork over the top to cover the ham.
Pass through the flour, then the beaten eggs and finally the breadcrumbs.
Carefully lay the pork into the fat fryer and fry for 3-4 minutes until golden-brown and cooked all the way through. (CAUTION: hot fat can be dangerous; never leave the pan unattended.)
Remove and drain onto kitchen paper then season with a little salt and freshly ground black pepper.
For the fries, carefully drop the potato julienne into the fat fryer in batches and fry for 3-4 minutes, or until golden-brown and crisp.
Remove with a slotted spoon and drain onto kitchen paper then season with salt and a little black pepper.
Place the pork onto the plate, pile the fries along side then finish with a dollop of ketchup, sprig of parsley and wedge of lemon.