Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized pieces and place them in a large mixing bowl.
Slice the zucchini into half-moons and the red bell pepper into thin strips, then add them to the bowl along with the broccoli florets.
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.
Drizzle the lemon-herb marinade over the chicken and vegetables, tossing thoroughly with your hands or tongs to ensure every piece is well-coated.
Spread the mixture in a single, even layer across the prepared baking sheet, making sure not to overcrowd the pan so the vegetables roast instead of steam.
Place the tray in the center of the oven and roast for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred edges.
Remove from the oven and garnish immediately with fresh chopped parsley before serving warm.