Combine first five ingredients in a small saucepan and simmer over medium heat for about ten minutes. Cool.
Wash chicken and pat dry. Place in a large resealable plastic bag and add marinade. Seal and shake, making sure everything is coated evenly. Place in the refrigerator for at least six hours, turning several times.
Preheat oven to 350 degrees and coat a thirteen by nine inch baking dish with non stick spray. Remove chicken from marinade and place in dish. Stir in peppers and pineapple. Bake until chick en is golden brown, about forty minutes, turning half way through cooking time. Sprinkle with sesame seeds to garnish. May be served hot or at room temperature.