Place the blueberries in the the bowl of a food processor and pulse until powdered. In a large bowl, combine the blueberries with the beef, salt and several turns of the pepper mill. Mix and knead the beef until all ingredients are evenly incorporated.
Form into 4 burgers. Pan-fry or grill according to your taste. If making cheeseburgers, add cheese about two minutes before the end of cooking time.
Place the burgers on buns and serve with ketchup or chilli sauce.