Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Trim the Brussels sprouts and cut them in half; chop the broccoli into bite-sized florets.
Drain and rinse the chickpeas, then pat them very dry with a clean kitchen towel to ensure they get crispy.
Place the chicken breast, broccoli, Brussels sprouts, and chickpeas on the prepared sheet pan.
Drizzle everything with the extra virgin olive oil and fresh lemon juice.
Sprinkle the dried oregano, garlic powder, sea salt, and black pepper evenly over the chicken and vegetables.
Toss the vegetables and chickpeas to coat, and rub the seasoning into both sides of the chicken.
Roast in the oven for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and browned.
Let the chicken rest for 5 minutes before slicing and serving with the roasted vegetable and chickpea medley.