Zuppa di pasta e fagioli, Slow version

I make this soup a lot and because of my planning challenge I often just use pre cooked beans instead of dry beans. In part because it seems like such a big use of energy to cook beans on the stovetop. So I adapted the favorite to the slow cooker to infuse the beans with the flavouring and deepen the umami. 

1 Tbsp. olive oil, plus 2 Tbsps. more, plus extra for drizzling

2–3 slices bacon (35–50g), cut into lardons

1 small onion (4oz/114g), roughly chopped

5 cloves garlic, smashed

¼ tsp. red pepper flakes, or more to taste

½ tsp. fennel seeds

5 fresh plum tomatoes (10oz/285g) or ½ can (14oz/398mL) diced tomatoes

1 lb. dry beans (or 2 lb. 5oz/1kg cooked)

  - preferably cranberry/borlotti, pinto or romano beans

5 cups water, plus more boiling water if needed

5 cups light beef broth (1 Tbsp. Better Than Bouillon)

2 bay leaves

30g Parmesan rind

Mustard green (or kale/chard) stems, sliced thin

8oz/230g small pasta such as shells, ditalini or orzo

Mustard green leaves (4–8oz), chopped (or kale/chard leaves)

1 tsp. salt, to taste

1 sprig fresh rosemary, finely chopped

⅓ cup (43g) grated Parmesan, plus more for serving

¼ cup roughly chopped fresh parsley

Freshly ground black pepper

1–2 tsps. white wine vinegar, optional

1. Render the lardons until lightly browned and crisp. Remove all but 1 Tbsp. of the fat and add the olive oil. 
2. Add the onion and cook until it begins to soften. 
3. Stir in the garlic, the red pepper flakes and the fennel seeds. Cook for a minute to toast the spices then add the tomatoes; cook until the tomatoes begin to break down.
4. Transfer everything to the slow cooker. Add the dry beans, water, broth, bay leaves, Parmesan rind and the stems from the mustard greens (or kale/chard). Cook on High for 5–6 hours (or Low for 8–10 hours), until the beans are completely tender.
5. When the beans are tender, remove about 2 ladles of the beans and broth, favouring the beans, and blend until smooth before returning everything to the soup pot and the stovetop. 
6. Bring the soup back to a gentle simmer. Add the greens and the pasta and cook another 15–20 minutes. The body of the soup comes in part from the pasta, so al dente isn't required or even desired here. 
7. The soup should be thick and creamy; if too thick, thin with a little more boiling water until you get the consistency you want.
8. Take off the heat and remove the bay leaves and Parmesan rind. Stir in the rosemary, salt, grated Parmesan, parsley and the remaining 2 Tbsps. olive oil. Let stand 2–3 minutes to allow the rosemary to perfume the soup before serving.
9. Serve with more Parmesan, olive oil, plenty of freshly ground black pepper and, if desired, a drizzle of white wine vinegar.