Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Cut the chicken breast into bite-sized cubes and place them in a large mixing bowl.
Add the rinsed and patted-dry chickpeas, broccoli florets, and chopped red bell pepper to the bowl.
Drizzle the mixture with olive oil and sprinkle with garlic powder, cumin, smoked paprika, sea salt, and black pepper.
Toss everything thoroughly until the chicken and vegetables are evenly coated in oil and spices.
Spread the mixture in a single layer on the prepared baking sheet, ensuring nothing is overcrowded.
Roast for 20-22 minutes until the chicken is cooked through and the chickpeas have developed a slight crunch.
While roasting, whisk together the tahini and lemon juice in a small bowl, adding a teaspoon of water if needed to reach a drizzling consistency.
Divide the roasted chicken and vegetable mixture into bowls and finish with the zesty tahini drizzle.