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 bite-sized pieces to ensure they cook quickly and evenly alongside the vegetables.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, minced garlic, oregano, salt, and pepper.
Place the chicken pieces, broccoli florets, sliced bell peppers, and zucchini half-moons onto the prepared sheet pan.
Drizzle the lemon-herb marinade over the chicken and vegetables, then toss thoroughly with your hands or tongs to coat every piece.
Spread the mixture into a single even layer, ensuring the pan isn't overcrowded so the ingredients roast and develop golden edges rather than steaming.
Bake for 18 to 22 minutes until the chicken is cooked through and the vegetables are tender-crisp.