Submerge 8 skewers into a baking dish filled with water. Set aside. Soaking the skewers will prevent the skewers from burning.
In a large bowl, whisk together olive oil, lemon juice/zest, minced garlic, greek seasoning, dried oregano, all-purpose seasoning, and pepper.
Cut the chicken tenderloins into 1 1/2-inch chunks. Cut the zucchini and orange/red bell peppers into large pieces. Add all of the vegetables to the marinade. Toss well. Marinate for 20 minutes.
Oven Method:
Preheat oven on medium broil. Line a large baking sheet with foil. Set aside.
Thread the chicken and vegetables alternately onto eight presoaked wooden skewers. Transfer to prepared baking sheet and place in oven to roast. Roast for 25-30 minutes until vegetables are tender and the chicken is cooked through, flipping every 10 minutes.
Grill method:
Preheat grill to high.
Thread the chicken and vegetables alternately onto eight presoaked wooden skewers. Grill until chicken is cooked through.