Ribollita is a hearty vegan pottage, full of seasonal vegetables, and bulked out with bread. Easy to make and incredibly frugal, it's perfect for chilly days!
In a large saucepan, gently fry the onion, carrot, celery, bay, rosemary, and a pinch of sea salt in 2 tablespoon oil over a medium heat for 10 minutes.
Add the garlic, potatoes, leek, and remaining oil, and continue to cook for another 10 minutes, stirring occasionally.
Add the tomato purée mixed with water, and the cabbage, kale, and chard, and stir well.
Tip the entire contents of 1 can of beans into a blender or food processor, plus the aquafaba from the other can, and 1.5 litres (6 cups) broth. (Set the drained beans aside for now.)
Blend for a few seconds, until you have a smooth bean broth (broda dei fagioli). Stir half of this into the pan.
Bring the soup to the boil, then reduce the heat, and simmer for around 2 hours, occasionally stirring in more bean broth until it's used up.
When the vegetables are cooked, and the soup is creamy, stir in the rest of the beans, plus the bread.
Cover, and set aside to rest for around 30 minutes, before serving into bowls, and seasoning with a few grinds of black pepper and a drizzle of extra virgin olive oil.
Store any leftovers in an airtight container in the 'fridge for up to a week.