2.Mix the beef, onion, Worcestershire sauce, egg and parsley together in a bowl. Season with a pinch of salt and pepper.
3.Shape into four burgers and set aside.
4.Put the chips into a pan of boiling water and cook for 3 minutes. Drain and place on kitchen paper to blot excess water.
5.Brush the chips with oil, place on a baking tray and cook for 40 minutes.
6.Ten minutes before the chips are cooked, grill the burgers for 6-8 minutes on each side. Slice open the buns and fill each with a burger, lettuce, tomato and ketchup. Serve with the chips.