Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized pieces and slice the zucchini into half-moon shapes.
Chop the broccoli into small, uniform florets and dice the red bell pepper into 1-inch squares.
In a large mixing bowl, whisk together the extra virgin olive oil, lemon juice, minced garlic, dried oregano, sea salt, and black pepper.
Add the chicken pieces and all the 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 baking sheet, ensuring the ingredients are not overcrowded so they roast properly.
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 while hot, optionally finishing with a fresh squeeze of lemon juice for extra brightness.