For the chips, bring a large pan of salted water to the boil, add the potatoes and boil for five minutes. Drain, then toss in the olive oil, season with sea salt and freshly ground black pepper and spread out on a baking tray.
Transfer to the oven for about 20 minutes, or until golden-brown and cooked through.
For the burgers, mix together all of the burger ingredients apart from the olive oil. Season with sea salt and freshly ground black pepper, divide the mixture in half and shape into two large burgers.
Heat the oil in a frying pan over a medium heat and fry the burgers for 4-5 minutes on each side, or until golden-brown and cooked through.
Serve the burger with the chips and tomato ketchup.