Preheat oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Cut the chicken breast into 1-inch bite-sized pieces and chop the broccoli, bell peppers, and zucchini into uniform pieces.
In a large bowl, whisk together the olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Add the chicken and vegetables to the bowl and toss until everything is evenly coated with the lemon-herb mixture.
Spread the mixture in a single layer on the prepared sheet pan, ensuring the pieces are not overcrowded to allow for even browning.
Roast for 18-22 minutes, or until the chicken is cooked through and the vegetables are tender and slightly charred at the edges.
Remove from the oven and serve immediately, optionally garnished with fresh parsley or extra lemon wedges.