Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
In a small glass bowl, whisk together the olive oil, lemon juice, minced garlic, dried oregano, sea salt, and black pepper to create the marinade.
Place the chicken breast on one side of the baking sheet and arrange the broccoli, carrots, and zucchini on the other side.
Drizzle the lemon-herb mixture over both the chicken and the vegetables, using your hands or a brush to ensure everything is evenly coated.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and slightly caramelized.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted vegetables.