Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Rinse the chickpeas and pat them very dry with a clean kitchen towel to ensure they roast up crispy.
Cut the chicken breast into 1-inch bite-sized cubes and chop the broccoli and bell pepper into similar sized pieces.
Place the chicken, chickpeas, broccoli, and peppers on the prepared baking sheet.
Drizzle the olive oil over the mixture and sprinkle with sea salt, black pepper, garlic powder, and smoked paprika.
Toss everything thoroughly with your hands or a spatula until evenly coated, then spread into a single layer.
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 drizzle with fresh lemon juice to brighten the flavors before serving.