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 pepper, and zucchini into uniform sizes.
In a small bowl, whisk together the olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Place the chicken and vegetables on the prepared sheet pan and pour the lemon-herb dressing over them, tossing well to ensure everything is evenly coated.
Spread the mixture into a single layer, ensuring the pieces are not overcrowded to allow for proper browning.
Roast for 18-22 minutes, or until the chicken is cooked through and the vegetables are tender-crisp with slightly charred edges.
Remove from the oven, sprinkle with fresh lemon zest, and serve immediately.