Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized cubes and chop the broccoli, bell pepper, and zucchini into uniform pieces to ensure even cooking.
Place the chicken and all the chopped vegetables directly onto the prepared sheet pan.
In a small mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Drizzle the lemon-herb mixture over the chicken and vegetables, then toss thoroughly with your hands or tongs until every piece is well coated.
Spread the ingredients out into a single, even layer across the pan, making sure not to overcrowd them so they roast rather than steam.
Bake for 18 to 22 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and slightly caramelized at the edges.
Remove from the oven and let rest for 5 minutes before serving or portioning into airtight containers for meal prep.