Combine the beef, Worcestershire sauce, tomato paste, egg, salt and pepper in a bowl. Shape into 4 large flat patties (larger than the buns you have chosen as the patties will shrink when cooked). Cook the onion rings in a frying pan over medium-high heat for 3 minutes each side. Add the patties and cook for 3 minutes each side or until cooked to your liking. Place the bun bases on serving plates and top with lettuce, a patty, tomato, beetroot, onion rings and condiments and sandwich with the bun tops. Serve with hot chips. Serves 4.
* To make cheeseburgers, top hot patties with a slice of cheese.