Prep: 1. Rinse and pick over beans. 2. Smash garlic. 3. Roughly chop: carrots, celery, onions. Make: 1. Add to slow cooker: 6 cups water, beans, barley, garlic, carrots, celery, onions, bay leaf, 1 1/2 tablespoons salt, pinch of pepper, herb blend, and porcini mushrooms (if using). 2. Squeeze tomatoes through your hands over the pot to break them down, and add with their juices. 3. Cover and cook on high until the beans are tender and the soup is thick, about 8 hours. 4. Add spinach and cheese, and stir until the spinach wilts, about 5 minutes. 5. Remove the bay leaf and season with salt and pepper to taste. 6. To serve, ladle soup into warmed bowls and drizzle each serving with vinegar and olive oil.
Dried porcini mushrooms can be a bit spendy, but really make this soup shine, you can often find less expensive dried mushrooms at Asian grocery stores. You could also substitute a few fresh mushrooms or leave them out if you prefer as well.