To make the marinade, mix together the salt, pepper, chipotle powder, garlic, cumin, cilantro and lime zest in a large bowl.
Add the chicken pieces to the marinade and coat chicken entirely.
Cover and refrigerate for 25 minutes.
Preheat grill on medium setting.
Dice the onion and bell peppers in same size pieces as chicken.
Pierce the chicken, onion and peppers into skewers.
Grill skewers for 4-5 minutes on each side or until chicken is white inside.
Remove skewers from heat and while warm, pour the lime juice over the skewers.