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 1-inch cubes and place them in a large mixing bowl.
Chop the red bell pepper and zucchini into bite-sized pieces, then add them to the bowl along with the broccoli florets.
In a small jar or bowl, whisk together the extra virgin olive oil, lemon juice, minced garlic, dried oregano, sea salt, and black pepper.
Pour the lemon-herb dressing over the chicken and vegetables, tossing thoroughly to ensure every piece is well-coated.
Spread the mixture in a single, even layer onto the prepared baking sheet to ensure even roasting.
Bake for 20-25 minutes, or until the chicken is cooked through and the vegetables are tender with slightly golden edges.
Remove from the oven and serve immediately, perhaps with an extra squeeze of fresh lemon if desired.