Heat a large saucepan over high heat. Add the oil and onion and cook for 2–3 minutes. Add the balsamic and sugar and cook for 1 minute. Add the tomato and stock, bring to the boil and cook for 10 minutes. Heat a small non-stick frying pan over high heat. Add the extra oil, capers and oregano and cook for 1 minute or until the capers and oregano leaves are crispy. Set aside. Stir the beans through the soup, ladle into bowls and top with the capers, oregano and parmesan to serve. Serves 4.