Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into uniform 1-inch bite-sized pieces and place them in a large mixing bowl.
Chop the broccoli into bite-sized florets, slice the bell pepper into strips, and cut the zucchini into half-moons.
In a small glass jar or bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, minced garlic, dried oregano, sea salt, and black pepper.
Add all the chopped vegetables to the bowl with the chicken, pour the lemon-herb dressing over the top, and toss thoroughly until every piece is well-coated.
Spread the mixture onto the prepared sheet pan in a single even layer, ensuring there is space between the pieces so they roast rather than steam.
Roast in the center of the oven for 20-25 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred, crispy edges.
Remove from the oven and serve immediately, optionally garnishing with fresh parsley or an extra squeeze of lemon.