Bring chicken broth to simmer in heavy large pot or Dutch oven over high heat. Add potato, yam, onion, carrots, broccoli, celery and ginger and bring to boil. Cover pot, reduce heat to medium and simmer soup until all vegetables are tender, about 30 minutes.
Puree soup in batches in blender just to chunky texture. Return soup to pot. Add corn and cooked chicken and simmer until corn is tender, about 5 minutes. Season soup to taste with salt and pepper. (Can be prepared 1 day ahead. Cover and refrigerate. Rewarm soup over low heat before serving.)
Ladle soup into bowls, sprinkle with chopped parsley and serve