Slow Cook:5 hrs to 6 hrs (low) or 2 1/2 to 3 hours (high)
Place chicken in a 3 1/2- or 4-quart slow cooker. In a small bowl stir together soy sauce, sherry, the water, sesame oil, ginger, vinegar, and garlic. Pour over chicken.
Cover and cook on low-heat setting for 5 to 6 hours or on high-heat setting for 2 1/2 to 3 hours. Transfer chicken to a serving platter, reserving cooking liquid in cooker. Cover chicken with foil and keep warm.
Stir bok choy into liquid in cooker. Cover and let stand for 5 minutes. Transfer bok choy to serving platter with chicken. Sprinkle chicken and bok choy with sesame seeds. If desired, spoon a little of the cooking liquid over chicken and bok choy.