Preheat oven to 400°F and line a large baking sheet with parchment paper.
Drain and rinse the chickpeas, then pat them very dry with a clean towel to ensure they get crispy.
Place the cubed chicken, dried chickpeas, broccoli florets, and sliced bell peppers onto the baking sheet.
Drizzle with olive oil and sprinkle with smoked paprika, garlic powder, sea salt, and black pepper.
Toss everything together until evenly coated and spread in a single layer.
Roast for 20 to 25 minutes, or until the chicken is cooked through and the vegetables are tender with charred edges.
In a small bowl, whisk together the tahini, lemon juice, and water until the dressing is smooth and creamy.
Divide the roasted mixture into bowls and drizzle with the lemon-tahini sauce before serving.