Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Cut the chicken breast into 1-inch bite-sized cubes and place them in a large mixing bowl.
Chop the bell pepper and zucchini into similar 1-inch pieces, then add them to the bowl along with the broccoli florets.
In a small jar or bowl, whisk together the extra virgin olive oil, minced garlic, lemon juice, dried oregano, sea salt, and black pepper.
Pour the lemon-herb dressing over the chicken and vegetables, tossing thoroughly to ensure everything is evenly coated.
Spread the mixture in a single layer across the prepared baking sheet, ensuring the pieces aren't too crowded so they roast rather than steam.
Roast for 20-25 minutes, or until the chicken is cooked through and the vegetables are tender and slightly caramelized at the edges.
Remove from the oven and serve immediately, optionally garnishing with fresh parsley or extra lemon zest.