Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized cubes and place them into a large mixing bowl.
Add the broccoli florets, chopped bell pepper, red onion wedges, and rinsed chickpeas to the bowl with the chicken.
In a small glass jar or bowl, whisk together the olive oil, fresh lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Pour the lemon-herb dressing over the chicken and vegetables, tossing thoroughly to ensure every piece is evenly coated with the aromatics.
Spread the mixture in a single layer on the prepared baking sheet, ensuring enough space between items so they roast and develop a golden color rather than steaming.
Roast for 20 to 25 minutes, tossing the ingredients halfway through, until the chicken is cooked through and the vegetables are tender with slightly charred edges.
Serve immediately while hot, perhaps with an extra squeeze of fresh lemon for added brightness.