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 slice the red bell pepper into thin strips.
Drain and rinse the chickpeas, then use a clean kitchen towel to pat them very dry to ensure they become crunchy in the oven.
Spread the chicken, chickpeas, broccoli, and bell peppers across the baking sheet and toss with olive oil, sea salt, black pepper, and garlic powder.
Roast for 20 to 25 minutes, tossing the ingredients halfway through, until the chicken is fully cooked and the chickpeas are golden.
While the bowl base roasts, whisk together the tahini and lemon juice in a small bowl, adding a splash of warm water until it reaches a smooth, pourable consistency.
Divide the roasted chicken and vegetable mixture into serving bowls and drizzle the creamy tahini sauce over the top before serving.