Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized cubes and chop the broccoli, bell pepper, and zucchini into uniform pieces to ensure they cook at the same rate.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Place the chopped chicken and all the vegetables onto the prepared sheet pan.
Drizzle the lemon-herb mixture over the ingredients and toss thoroughly with your hands or tongs until everything is well-coated.
Spread the mixture out into a single, even layer, making sure not to overcrowd the pan so the vegetables roast rather than steam.
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 caramelized at the edges.