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 pieces for even cooking.
Slice the zucchini into half-moons and chop the red bell pepper into 1-inch squares.
In a large mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, minced garlic, dried oregano, sea salt, and black pepper.
Add the chicken pieces, broccoli florets, zucchini, and bell peppers to the bowl and toss thoroughly until everything is well coated in the lemon-herb marinade.
Spread the chicken and vegetable mixture onto the prepared baking sheet in a single, even layer.
Roast in the center of the oven for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender and lightly browned.
Remove from the oven and serve immediately while hot.