My favourite ribollita (La mia ribollita preferita)

INGREDIENTS

• 310 g zolfini or cannellini beans, fresh, or dried and soaked overnight
• 1 bay leaf
• 1 tomato, squashed
• 1 small potato, peeled
• 2 small red onions, peeled
• 2 carrots, peeled
• 3 sticks celery, trimmed
• 3 cloves garlic, peeled
• olive oil
• 1 pinch ground fennel seeds
• 1 pinch dried red chilli
• 400 g good-quality tinned plum tomatoes
• 310 g cavolo nero, leaves and stalks finely sliced
• 2 large handfuls good-quality stale bread, torn into chunks
• sea salt
• freshly ground black pepper
• extra virgin olive oil