Heat oil in large saucepan over medium-high heat. Stir in chard stems, leeks, carrots, celery, and nutmeg. Cook 7 to 9 minutes, or until vegetables release juices but are still brightly colored, stirring often.
Add broth, barley, and 1 1/2 cups water. Cover, and bring to a boil. Reduce heat and simmer, covered, 45 minutes, stirring halfway through. Add lima beans and chard leaves. Simmer 10 minutes more, or until lima beans are tender.