01 - In a large mixing bowl, whisk together the olive oil, lemon juice, Greek yogurt, minced garlic, red wine vinegar, dried oregano, thyme, salt, black pepper, and lemon zest until well combined.
02 - Add the chicken cubes to the marinade and toss until every piece is evenly coated. Cover the bowl with plastic wrap and refrigerate for at least 1 hour, or up to 8 hours for deeper flavor penetration.
03 - If using wooden skewers, submerge them in water and soak for at least 30 minutes to prevent burning on the grill.
04 - Thread the marinated chicken pieces onto skewers, alternating with red onion chunks, bell pepper pieces, and zucchini rounds, distributing the ingredients evenly across each skewer.
05 - Preheat an outdoor grill or grill pan to medium-high heat. Lightly oil the grates to prevent sticking.
06 - Place the skewers on the grill and cook for 6 to 8 minutes per side, turning once, until the chicken is cooked through to an internal temperature of 165°F and has slight charring on the edges.
07 - Remove the kabobs from the grill and serve immediately with fresh lemon wedges, a sprinkle of chopped parsley, and tzatziki sauce on the side.