1. Mix all ingredients thoroughly in a large bowl.
2. Divide into burgers approximately 2cm thick, and make a shallow dent in each one with the back of a spoon or your thumb – this keeps them flatter as they cook.
3. Heat the oil in a heavy-bottomed pan and fry over a medium heat until cooked, juicy and nicely browned on both sides.
4. Place in a warm place to rest while you prepare the buns and accompaniments – a selection of lettuce, tomato, gherkins, cheese, mustard, mayo and relishes always go down well.