Barley and Potato Soup

10 cups low-sodium vegetable broth
1 cup dry pearled barley
1 lbs red-skinned potatoes, quartered
1 cup sliced carrots
1 cup sliced fennel bulb
1 cup sliced leeks
1 package arugula (5 oz)
2 tbsp chopped fresh dill
2 tbsp fresh lemon juice
1 tsp kosher salt
black pepper to taste
lemon zest

1) Boil broth and barley in a large pot over high heat. Once boiling, reduce heat to medium and simmer 50-55 minutes
2) Add potatoes, carrots, fennel, and leeks and simmer until fork-tender, 15-20 minutes
3) Stir in arugula, dill, lemon juice and salt. Season soup with pepper and garnish each serving with lemon zest