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 cubes and chop the broccoli, bell pepper, and zucchini into similar bite-sized pieces.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, garlic powder, dried rosemary, dried thyme, sea salt, and black pepper.
Place the chicken cubes and chopped vegetables onto the prepared baking sheet in a single layer.
Drizzle the lemon-herb marinade over the chicken and vegetables, then toss thoroughly with your hands or tongs to ensure every piece is well-coated.
Spread the mixture out across the pan so nothing is overcrowded, which ensures the ingredients 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 with slightly browned edges.
Remove from the oven and let rest for 2 minutes before serving to allow the juices to redistribute.