Place chicken in a stock pot. Pour in enough water to cover chicken. Add ginger and salt; bring to a boil. Reduce heat, cover, and gently simmer for 1 hour to 1 1/2 hours.
Strain broth, and return broth to stock pot. Let chicken cool, then remove bones and skin, and tear into bite-size pieces; set aside.
Stir rice and onion into broth, and bring to a boil. Reduce heat to medium, and cook for 30 minutes, stirring occasionally. If necessary, adjust with water or additional salt, cook an additional 45 minutes for a thick consistency.
Ladle soup into bowls, and top with chicken and pepper.