Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Dice the chicken breast into uniform 1-inch cubes to ensure even cooking.
Chop the broccoli into small florets, slice the bell pepper into strips, and quarter-round the zucchini.
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 cubes and chopped vegetables to the bowl, tossing thoroughly until every piece is well-coated with the marinade.
Spread the mixture onto the prepared baking sheet in a single layer, making sure not to overcrowd the pan so the vegetables roast rather than steam.
Place the sheet in the oven and roast for 18 to 22 minutes, or until the chicken is cooked through and the vegetables have slightly charred, caramelized edges.
Remove from the oven and garnish with freshly chopped parsley before serving warm.