Cut the chicken breast, bell peppers, zucchini, and red onion into uniform 1-inch cubes.
In a small bowl, whisk together the extra virgin olive oil, lemon juice, minced garlic, dried oregano, sea salt, and black pepper to create the marinade.
Place the chicken and vegetables in a large bowl or resealable bag, pour the marinade over them, and toss until everything is thoroughly coated.
Thread the marinated chicken and vegetables onto skewers, alternating between the chicken and different colored vegetables.
Preheat your grill or grill pan to medium-high heat.
Grill the kabobs for 10 to 12 minutes, turning every few minutes, until the chicken is cooked through and the vegetables are tender with light char marks.
Remove from the heat and let rest for 2 minutes before serving.