Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized cubes and slice the bell pepper and zucchini into similar sized pieces.
In a small bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Place the chicken cubes, broccoli florets, bell peppers, and zucchini onto the prepared sheet pan.
Drizzle the lemon-herb dressing over the chicken and vegetables, then toss thoroughly with your hands or tongs to ensure everything is evenly coated.
Spread the mixture out into a single layer, ensuring the pan isn't overcrowded so the vegetables roast rather than steam.
Roast in the oven for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender and slightly caramelized at the edges.
Remove from the oven and serve immediately, optionally garnished with fresh parsley or extra lemon wedges.