Place soy, sherry, vinegar, brown sugar, and ginger in a medium bowl and stir with a whisk to blend. Makes ⅔ cup marinade - measure out and reserve ⅓ cup. Trim all visible fat from chicken and add chicken to marinade in bowl; stir to coat. Allow to marinate for 20 to 30 minutes (may marinate longer - cover and refrigerate). Pour remaining marinade over pineapple slices and marinate for 20 to 30 minutes. Preheat the Cuisinart™ Griddler in the open grill position to High (375°). Drain the pineapple; reserve marinade in a small sauce pan. When hot, grill the pineapple slices for 2½ to 3 minutes per side. Remove to a warm plate and cover loosely. Drain the chicken - add the marinade to the saucepan and bring to a boil. Reduce heat to low and simmer until chicken is ready (do not save and use marinade as a sauce unless you do this step). Arrange the chicken, "skin" side down evenly spaced on the grill. Grill for 5 to 6 minutes per side - chicken juices should run clear and test 170°F when checked with an instant read thermometer. Transfer to warm plate and pour the simmered reserved sauce over the chicken. Serve with steamed brown or white rice.