Lemon Chicken Soup with Spaghetti

8 c low-sodium chicken broth
1/3 c fresh lemon juice (about 2 lemons)
1 dried bay leaf
1 (2-inch) piece Parmesan cheese rind
2 medium carrots, peeled and chopped
2 stalks celery, chopped
1 c chopped onion
1 c (about 2 1/2 oz) spaghetti, broken into 2-inch pieces (or any short pasta)
2 c diced cooked rotisserie chicken
1 c grated Romano cheese (or Parmesan)
1/4 c chopped fresh flat-leaf parsley
kosher salt

In large stockpot, bring chicken broth, lemon juice, bay leaf, and Parmesan rind to a boil over medium-high heat. Meanwhile, saute carrots, celery and onion to soften. Add to chicken broth mixture. Add broken pasta and cook pasta til tender, stirring occasionally. Add chicken and heat through. Remove bay leaf and Parmesan rind and discard. Stir in 1/2 of the cheese and parsley. Season with salt, to taste. Ladle soup into bowls and sprinkle with remaining cheese. Garnish with flat-leaf parsley.