Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Slice the chicken breast into 1-inch bite-sized pieces and chop the broccoli, bell pepper, and zucchini into uniform chunks to ensure even cooking.
In a small bowl, whisk together the extra virgin olive oil, lemon juice, minced garlic, dried oregano, sea salt, and black pepper to create the marinade.
Place the chicken and chopped vegetables onto the prepared sheet pan and pour the lemon-herb dressing over them.
Toss everything thoroughly with your hands or tongs until every piece is well-coated in the oil and spices.
Spread the mixture out into a single layer, ensuring the pan isn't overcrowded so the ingredients roast rather than steam.
Roast for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender with slightly caramelized edges.
Remove from the oven and serve immediately, optionally finishing with a fresh sprinkle of herbs or an extra squeeze of lemon.