Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Dice the chicken breast into uniform 1-inch cubes and chop the zucchini, bell pepper, and broccoli into bite-sized pieces.
In a small mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, minced garlic, dried oregano, sea salt, and black pepper.
Place the chicken and all the vegetables onto the prepared baking sheet.
Pour the lemon-herb dressing over the chicken and vegetables, tossing thoroughly with your hands or tongs to ensure every piece is well-coated.
Spread the mixture out into a single, even layer so the ingredients roast and develop color rather than steaming.
Roast in the center of the oven for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender and slightly charred.
Remove from the oven and garnish with freshly chopped parsley before serving warm.