Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Dice the chicken breast into 1-inch cubes and place them in a large mixing bowl.
Slice the red bell pepper into strips and the zucchini into half-moons, 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 evenly coated.
Spread the mixture out in a single layer on the prepared baking sheet, ensuring the pieces aren't too crowded to allow for even roasting.
Roast in the center of the oven 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 let rest for 2 minutes before serving.