Preheat the oven to 220°C (425°F), or 200°C fan-forced.
In a jug, combine all marinade ingredients and mix well.
Place potatoes, onion, and capsicum in a large baking dish. Add 1 tablespoon of marinade and toss to coat. Spread evenly.
Add the remaining marinade to the chicken and coat thoroughly.
Arrange the marinated chicken on top of the vegetables in a single layer.
Roast for 28 minutes or until the chicken is fully cooked and potatoes are tender.
Turn on the grill (broiler) and cook for an additional 2 minutes to crisp the edges.
Finish with feta, dill, olive oil drizzle, and cracked pepper.
Serve your Chicken Souvlaki Tray Bake with pita, tzatziki, and lemon wedges.