Combine the 1 teaspoon garlic powder, ½ cup rice vinegar, ½ cup soy sauce, 2 tablespoons Hoisin sauce, ¾ cup brown sugar, 2 teaspoons sesame oil, 1 tablespoon sesame seeds, and ½ teaspoon ginger. Mix together the ⅓ cup hot water and 1 tablespoon peanut butter until smooth and add this to the marinade.
Place the chicken breast pieces and marinade in a sealable Ziplock bag and marinate for at least 3 hours.
Place the marinated chicken on the skewers alternating with the bell pepper pieces in between.
Grill on medium-high heat for about 5-7 minutes on each side or until the chicken is no longer pink.
Optional: While the chicken is cooking, place the marinade in a medium-sized saucepan. Bring to a boil for about 4-5 minutes then turn to low and simmer until the chicken is done cooking. Pour over the cooked chicken skewers for extra sauce.