Combine the escarole, garlic, and oil in a large heavy saucepan. Cook over low heat, covered, stirring occasionally, until escarole is tender, about 15 minutes.
Add the broth, carrot, and salt. Heat to a simmer, cover, and cook until carrots are just tender, about 5 minutes. Add pasta to soup.
Just before serving, heat soup to a simmer. Place lemon ze