Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized cubes and place them in a large mixing bowl.
Chop the broccoli into small florets, slice the red bell pepper into thin strips, and cut the zucchini into half-moon slices.
In a small jar or bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Add the vegetables to the bowl with the chicken and pour the lemon-herb dressing over the top, tossing thoroughly to coat every piece.
Spread the chicken and vegetable mixture onto the prepared sheet pan in a single layer, ensuring they are not overcrowded to allow for even roasting.
Roast in the oven for 20-25 minutes, or until the chicken is cooked through and the vegetables are tender and slightly caramelized at the edges.