Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Dice the chicken breast into 1-inch cubes and chop the bell pepper, zucchini, and red onion into uniform bite-sized pieces.
Drain and rinse the chickpeas, then pat them thoroughly dry with a clean kitchen towel to ensure they roast until crisp.
In a large mixing bowl, combine the chicken, chickpeas, and vegetables with the olive oil, garlic powder, cumin, smoked paprika, sea salt, and black pepper.
Toss the mixture until everything is evenly coated in oil and spices, then spread it in a single layer across the baking sheet.
Roast for 20 to 25 minutes, tossing the ingredients halfway through, until the chicken is cooked through and the vegetables have slightly charred edges.
Remove from the oven, drizzle the fresh lemon juice over the hot sheet pan, and garnish with chopped fresh parsley before serving.