Preheat your 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 and slice the zucchini and bell peppers.
Place the chicken, broccoli, zucchini, and peppers onto the prepared sheet pan.
In a small bowl, whisk together the olive oil, lemon juice, minced garlic, oregano, sea salt, and black pepper.
Drizzle the lemon-herb mixture over the chicken and vegetables, tossing well to ensure everything is evenly coated.
Spread the ingredients out in a single layer to ensure even roasting and browning.
Roast for 18-22 minutes, or until the chicken is cooked through and the vegetables are tender-crisp.
Serve immediately, garnished with an extra squeeze of fresh lemon if desired.