Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Pat the chicken breast dry with paper towels and cut into uniform 1-inch bite-sized pieces.
Rinse and drain the chickpeas, then roll them between two paper towels to remove as much moisture as possible for maximum crunch.
Chop the broccoli into small florets, slice the red bell pepper into thin strips, and cut the red onion into small wedges.
Place the chicken, chickpeas, broccoli, peppers, and onions onto the prepared baking sheet in a single layer.
Drizzle the olive oil over the mixture and sprinkle evenly with garlic powder, smoked paprika, sea salt, and black pepper.
Toss everything thoroughly with your hands or tongs to ensure an even coating of oil and spices.
Roast for 20 to 25 minutes, tossing the ingredients halfway through, until the chicken is cooked through and the chickpeas are slightly crisp.
Remove from the oven and immediately drizzle with fresh lemon juice and garnish with chopped fresh parsley before serving.