Rinse and dry chicken breasts. Place chicken in a medium Dutch oven or other pot with tight fitting lid. Add a few bay leaves to pot. Peel and quarter an onion, leaving the root end in tact. Arrange with chicken and bay leaves then add water to the pot to come up to the top of chicken without covering it. Bring to a boil and drop heat to simmer. Cover pot and poach chicken about 15-20 minutes. Cool meat, strain and reserve 2 cups of cooking liquid. Remove skin and bones and shred meat into small pieces with forks or your hands.