Slow Cooker Ribollita

If you're using canned beans, use 2 14-ounce cans, drained and well-rinsed.

3 tablespoons extra-virgin olive oil, plus more for drizzling
4 celery stalks, chopped
3 medium cloves garlic, chopped
2 medium carrots or equiv. winter squash, chopped
1 medium red onion, chopped
1/2 teaspoon crushed red pepper flakes
1 1/2+ teaspoons fine grain sea salt
4 cups / 22 oz / 620g cooked white beans
1 14-ounce / 400 ml can crushed tomatoes

1 pound / 16 ounces / 450g cavolo nero (lacinato kale, Tuscan kale), stems trimmed off and leaves well chopped

1/2 pound / 8 oz / 225g crustless loaf of bread
zest of one lemon
to serve: lots of well-chopped oily black olives, sliced scallions (opt.)

Heat the olive oil, celery, garlic, carrots, red onion, red pepper flakes, and salt in a large pot over medium-high heat. If you have an Instant Pot or other multi-cooker, you can do this directly in the device. Cook for 10 minutes, sweating the vegetables, but avoid any browning. Mash 1 cup of the beans into a puree (a mortar and pestle works great here), and add these to the pot along with the remaining 3 cups of beans. Stir in 8 cups / 2 liters of water. Slow cook on LOW for 6-8 hours.

Roughly an hour before you're ready to serve, stir in the tomatoes, kale, torn up pieces of the bread, and lemon zest.

Serve immediately, or cool and refrigerate overnight. Serve reheated, or "ribollita" meaning reboiled, the next day ladled into bowls. Finish each serving with a drizzle of olive oil and some chopped olives, perhaps some scallions.

Makes a large pot of soup - enough for 10 servings.