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 prepare the broccoli, bell peppers, and zucchini by chopping them into uniform pieces.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper until well combined.
Place the chicken cubes and all the chopped vegetables onto the prepared sheet pan.
Drizzle the lemon-herb oil mixture over the chicken and vegetables, then use your hands or tongs to toss everything until thoroughly and evenly coated.
Spread the mixture out into a single layer, ensuring the chicken pieces are not crowded so they brown properly.
Roast in the center of the oven for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred edges.