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 uniform 1-inch cubes and chop the broccoli, bell pepper, and zucchini into similar bite-sized pieces.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, minced garlic, oregano, sea salt, and black pepper.
Place the chicken and all chopped vegetables onto the sheet pan and drizzle the lemon-herb marinade over the top.
Toss the ingredients thoroughly with your hands or tongs until every piece is well-coated in the fragrant oil and spices.
Spread the mixture out into a single layer, ensuring the chicken pieces are spaced out to allow for proper roasting rather than steaming.
Bake for 18 to 22 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender with slightly charred edges.
Remove from the oven and serve immediately, optionally garnishing with fresh parsley or an extra squeeze of lemon.