Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into uniform 1-inch cubes to ensure even cooking and a consistent texture.
Chop the broccoli, red bell pepper, zucchini, and red onion into bite-sized pieces, keeping them similar in size to the chicken.
In a large mixing bowl, combine the chicken and vegetables, then drizzle with the extra virgin olive oil.
Sprinkle the dried oregano, garlic powder, sea salt, and black pepper over the mixture and toss thoroughly until everything is well-coated.
Spread the mixture in a single layer on the prepared baking sheet, ensuring it is not overcrowded so the vegetables roast rather than steam.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender.
Remove from the oven and garnish with freshly chopped parsley before serving warm.