Greek Chicken Kebabs

Name: Greek Chicken Kebabs
Ingredients: 1 3/4 – 2 lbs bonless skinless chicken breasts, diced into 1 1/4-inch cubes; 1/4 cup + 2 Tbsp olive oil, divided, plus more for grill; 3 Tbsp fresh lemon juice; 1 Tbsp red vinegar; 3 cloves garlic, minced; 2 tsp dried oregano; 1/2 tsp dried basil; 1/2 tsp dried thyme; 1/2 tsp ground coriander; Salt and freshly ground black pepper; 2 large red bell peppers, diced into 1 1/4-inch pieces; 3 small zucchini (nearly 1 lb), sliced into rounds slightly under 1/2-inch thick; 1 large red onion, diced into 1 1/4-inch wedges