- 1 cup dried multibean mix or Great Northern beans, picked over and rinsed
- 6 cups water
- 1 (14-ounce) can whole tomatoes, with juice
- 3 cloves garlic, smashed
- 2 ribs celery, chopped
- 2 medium carrots, chopped
- 1/2 medium onion, chopped
- 1/2 cup pearl barley
- 1 bay leaf
- 1 1/2 tablespoons kosher salt, plus additional for seasoning
- 2 teaspoons dried Italian herb blend
- Freshly ground black pepper
- 1/2 ounce dried porcini mushrooms, optional
- 3 cups cleaned baby spinach leaves (about 3 ounces)
- 1 cup freshly grated Parmesan
- 1 tablespoon balsamic vinegar
- Extra-virgin olive oil
Put beans, water, tomatoes and their juices, garlic, celery, carrots, onion, barley, bay leaf, 1 1/2 tablespoons salt, herb blend, pepper, and porcini mushrooms (if using) in a slow cooker; cover and cook on LOW until the beans are quite tender and the soup is thick, about 8 hours.
Stir in the spinach, cheese, and vinegar, cover, and let the soup cook until the spinach wilts, about 5 minutes. Taste and season with salt and black pepper, to taste.
Ladle the soup into warmed bowls and drizzle each serving with olive oil.
Per Serving (based on a 4-serving yield): Calories: 463; Total Fat: 16 grams; Saturated Fat: 5 grams; Protein: 23 grams; Total carbohydrates: 61 grams; Sugar: 11 grams; Fiber: 16 grams; Cholesterol: 4 milligrams; Sodium: 2693 milligrams