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 uniform 1-inch bite-sized pieces to ensure even roasting.
Chop the broccoli florets, red bell pepper, and zucchini into similar sizes so they cook at the same rate as the chicken.
In a large mixing bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Add the chicken and all the chopped vegetables to the bowl, tossing thoroughly until every piece is well-coated with the marinade.
Spread the chicken and vegetable mixture across the prepared sheet pan in a single layer, making sure not to overcrowd the pan.
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 caramelized edges.
Remove from the oven and serve immediately, optionally finishing with a fresh squeeze of lemon juice for extra brightness.