Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Rinse and drain the chickpeas, then pat them very dry with a clean kitchen towel to ensure they achieve a crispy texture.
Dice the chicken breast into 1-inch cubes and chop the broccoli and bell pepper into bite-sized pieces.
Place the chicken, chickpeas, broccoli, and peppers on the prepared baking sheet and toss with olive oil, garlic powder, smoked paprika, salt, and pepper.
Spread the ingredients into a single layer and roast for 20 to 25 minutes, tossing halfway through, until the chicken is cooked through and the chickpeas are golden.
While the bowl base roasts, whisk together the tahini and lemon juice in a small bowl, adding a teaspoon of warm water if needed to reach a pourable consistency.
Divide the roasted mixture into a bowl and drizzle the creamy tahini dressing over the top before serving warm.