Mix all ingredients together in a large-container. Toss in the bell peppers, red onion, chicken and other ingredients. Cover and let cool in the fridge for at least 8 hours or overnight.
Preheat the oven to 450°F. Line a baking sheet with aluminum foil or other material. Thread the marinated chicken and vegetables on skewers and bake for 20-25 minutes, or till cooked through & golden-brown. Flip the skewers halfway through.
Optional: Switch the oven to broil for 2-3 minutes to get a lightly charred look. Serve immediately with lemon wedges and/or parsley.