Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Rinse the chickpeas and pat them very dry with a clean kitchen towel; removing moisture is key for a crispy texture.
Cut the chicken breast into bite-sized 1-inch cubes and chop the red bell pepper into similar sized pieces.
In a large mixing bowl, combine the chicken, dried chickpeas, broccoli florets, and bell peppers.
Drizzle the olive oil over the mixture and sprinkle with cumin, smoked paprika, garlic powder, sea salt, and black pepper.
Toss everything together until the chicken and vegetables are thoroughly and evenly coated in the spice blend.
Spread the mixture in a single layer on the prepared baking sheet, ensuring the ingredients aren't crowded so they roast rather than steam.
Roast for 20 to 25 minutes, tossing the ingredients halfway through, until the chicken is cooked through and the chickpeas are golden.
Remove from the oven and immediately drizzle the fresh lemon juice over the hot tray to brighten the flavors before serving.