Put the oil and onion in a large saucepan over medium heat. Cook 5 minutes or until lightly browned, stirring occasionally. Stir in rosemary, escarole, salt, and pepper; cook until escarole wilts and all the liquid has evaporated. Add water, beans, barley, and bouillon. Bring to a boil; reduce heat, and simmer for 30 minutes or until the barley is tender.
Wine Note: A classic Tuscan comfort food such as this dish calls for Tuscany's famous comfort wine: Chianti. Brolio's affordable 1997 Chianti Classico ($16) befits the humbleness of this soup.