Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch cubes and chop the broccoli, bell pepper, and zucchini into uniform, bite-sized pieces.
In a large mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Add the chicken cubes and chopped vegetables to the bowl, tossing thoroughly until every piece is evenly coated with the herb-oil mixture.
Spread the chicken and vegetables in a single layer on the prepared sheet pan, ensuring they are not overcrowded so they roast rather than steam.
Place the pan in the oven and roast for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred edges.
Remove from the oven and serve immediately, perhaps with an extra squeeze of fresh lemon for added brightness.