The oil-rich Garlic Croûtons add texture and flavour to this simple soup. If you don’t have time to make any, serve the soup with slices of toasted ciabatta bread instead.
Bring a large, covered saucepan of unsalted water to the boil. Drain the beans and add them to the pan. Return to the boil and boil vigorously for 10 minutes.
Meanwhile, put the carrot, celery, garlic, onion and sage in the slow cooker.
Drain and rinse the beans, then transfer them to the cooker. Pour over the stock and oil and season with pepper. Add extra stock to just cover t