Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch cubes and slice the zucchini into rounds and the bell pepper into strips.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper.
Place the chicken cubes, broccoli florets, bell pepper strips, and zucchini slices onto the prepared baking sheet.
Pour the lemon-herb marinade over the chicken and vegetables, tossing thoroughly with your hands or tongs to ensure every piece is evenly coated.
Spread the ingredients out into a single layer, ensuring they are not overcrowded so they roast rather than steam.
Bake for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender with slightly browned edges.
Remove from the oven and serve immediately while hot.