Trim chicken breasts, and cut the chicken into same-size cubes about 2 inches square.
Mix the olive oil, lemon juice, black pepper, Spike Seasoning, pureed garlic, dried basil, dried oregano, dried sage, and onion powder to make the marinade.
Put the chicken in a large Ziploc bag and pour in the marinade and seal the bag.
Marinate the chicken in the refrigerator for at least 4 hours. (If you can marinate it longer, that will only improve the flavor. I like to marinate overnight and cook chicken later the next day.)
Peel onion and cut into pieces about 2 inches square. Cut ends off red pepper, remove seeds, and cut the pepper into pieces about 2 inches square. If you're using zucchini, cut off ends, cut in half lengthwise, and then cut pieces that are 2 inches wide.
Put chunks of red pepper, red onion, and zucchini (if using) into a container and store in refrigerator while the chicken marinates.
About 1-2 hours before you want to cook the kabobs, add the vegetables to the bag with the chicken and continue to marinate in refrigerator.
When you want to assemble kabobs, drain the chicken and veggies and let ingredients come to room temperature.
Spray the grill with nonstick spray or brush with a high smoke point oil, and preheat grill to high while you assemble the kabobs.
To assemble kabobs, first we laid them out on the cutting board evenly divided into four rows so all our kabobs would be the same. (You might actually prefer to vary them if some family members prefer certain ingredients.)
Thread ingredients onto kabob skewers, pressing tightly together.
Put kabobs on the grill and turn grill down to medium-high.
Turn kabobs when you see grill marks, cooking about 3-4 minutes on each side or a total cooking time of about 12-16 minutes. (Cooking the kabobs on all four sides is definitely easier if all your pieces are the same size, otherwise they want stay up on all the sides.
Kabobs are done when chicken feels firm (not hard) to the touch and veggies are lightly browned.
Serve hot.