Chicken breast, green pepper, and onion cut into cubes.
For the marinade: mix salt, black pepper, dijon mustard, and olive oil.
In a bowl, toss all the ingredients and mix with the 1/3 marinade.
On metal or soaked wooden skewers, alternately thread chicken and vegetables.
discard remaining marinade in the bowl — place kabobs on an oiled baking sheet rack over medium heat.
Grill, covered, until chicken is no longer pink, 8-10 minutes, turning occasionally; frequently baste with reserved marinade during the last 3 minutes.