Preheat oven to 400°F and line a large baking sheet with parchment paper.
Pat the chicken breast dry and cut into 1-inch bite-sized pieces.
Rinse and drain the chickpeas, then pat them very dry with a clean towel to ensure they get crispy.
In a large bowl, toss the chicken, chickpeas, broccoli, and sliced bell peppers with olive oil, garlic powder, smoked paprika, salt, and pepper.
Spread the mixture in a single layer on the prepared baking sheet.
Roast for 20-25 minutes, tossing halfway through, until the chicken is cooked through and the chickpeas are golden and crisp.
Remove from the oven and drizzle with fresh lemon juice before serving.