elaine's tuscan ribollita

Ingredients

• 1/4 cup extra-virgin olive oil, plus some for drizzling
• 1 large onion, chopped
• 1 - leek, sliced lengthwise to rinse and then into ¼-inch crosswise slices
• 1 - carrot, chopped
• 4 ounces pancetta or streaky bacon, chopped
• 2 cloves garlic, minced
• 1 teaspoon salt
• 1 teaspoon freshly ground black pepper
• 1 can tomato paste
• 1 can diced tomatoes (19 oz) or 1 ½ lb frozen tomatoes
• 1 pound frozen spinach, thawed and squeezed dry (or beet greens or kale)
• 1 can cannelloni beans, drained (15 oz - may use red kidney beans, chickpeas or your favourite beans)
• 1 tablespoon herbs de provence
• 1 pinch peperoncino (pepper flakes), optional
• 1 - bay leaf
• 3 cups chicken stock
• 1 - 3-inch piece Parmesan rind, optional
• 3 cups cubed day-old (preferably Italian) bread or rolls
• - grated Parmesan, for serving