Combine undrained pineapple, oregano and garlic powder in shallow, nonmetallic dish. Add chicken, turn to coat all sides. Cover and marinate 15 minutes in refrigerator. Grill or broil chicken and pineapple, brushing with reserved marinade, 5 to 8 minutes on each side or until chicken is no longer pink in center and pineapple is golden brown. Discard any remaining marinade. Combine salad dressing, jicama and red pepper. Spread onto bottom halves of rolls. Top with chicken, bell pepper rings and pineapple and top halves of rolls. Garnish with fresh fruit and mint leaves, if desired.