Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Slice the chicken breast into 1-inch bite-sized cubes and chop the broccoli, bell pepper, and zucchini into similar uniform pieces.
In a large mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, minced garlic, dried oregano, sea salt, and black pepper.
Add the chicken cubes and chopped vegetables to the bowl, tossing thoroughly until every piece is evenly coated in the herb marinade.
Spread the mixture in a single layer across the prepared sheet pan, ensuring there is enough space between the pieces to allow for proper roasting.
Bake for 18 to 22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly caramelized edges.
Remove from the oven and serve immediately, optionally garnishing with a fresh squeeze of lemon for extra brightness.