Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Dice the chicken breast into uniform 1-inch cubes to ensure even cooking.
Peel the sweet potato and cut into 1/2-inch cubes; chop the broccoli and red bell pepper into bite-sized pieces.
Rinse and drain the chickpeas, then pat them thoroughly dry with a clean kitchen towel to help them get crispy.
Place the chicken, sweet potatoes, chickpeas, broccoli, and peppers onto the prepared sheet pan.
Drizzle the olive oil and balsamic vinegar over the ingredients.
Sprinkle the dried oregano, garlic powder, sea salt, and black pepper evenly across the pan.
Use your hands or a spatula to toss everything together until every piece is well-coated in oil and seasonings.
Spread the mixture into a single layer, ensuring the chicken and vegetables aren't too crowded.
Roast in the center of the oven for 25 to 30 minutes, tossing halfway through, until the chicken is cooked through and the sweet potatoes are tender.