Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized pieces and chop the broccoli, bell pepper, and zucchini into uniform chunks.
In a large mixing bowl, whisk together the olive oil, lemon juice, garlic powder, dried oregano, dried thyme, sea salt, and black pepper.
Add the chicken and all the chopped vegetables to the bowl, tossing thoroughly until every piece is evenly coated in the herb marinade.
Spread the chicken and vegetable mixture in a single layer across the prepared baking sheet, ensuring they aren't overcrowded so they roast rather than steam.
Roast in the center of the oven for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred edges.