Preheat oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Cut the chicken breast into 1-inch bite-sized pieces.
Chop the broccoli into florets, slice the zucchini into half-moons, and dice the bell pepper into 1-inch squares.
In a small bowl, whisk together the olive oil, minced garlic, lemon juice, dried oregano, sea salt, and black pepper.
Place the chicken and vegetables on the prepared sheet pan.
Drizzle the lemon-herb mixture over the ingredients and toss thoroughly to ensure everything is evenly coated.
Spread the mixture in a single layer, ensuring no overcrowding for optimal roasting.
Roast for 20-25 minutes, or until the chicken is cooked through and the vegetables are tender and slightly caramelized.