Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Cut the chicken breast into 1-inch bite-sized pieces and place them in a large mixing bowl.
Add the broccoli florets, bell pepper strips, and zucchini slices to the bowl with the chicken.
In a small jar or bowl, whisk together the olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Pour the lemon-herb mixture over the chicken and vegetables and toss thoroughly to ensure everything is evenly coated.
Spread the mixture in a single, even layer on the prepared baking sheet.
Roast 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 serve immediately, optionally garnished with fresh parsley or an extra squeeze of lemon.