Preheat your oven to 400°F and line a large sheet pan with parchment paper.
Pat the chicken breast dry with a paper towel and cut into 1-inch bite-sized pieces.
Rinse and drain the chickpeas, then pat them thoroughly dry with a clean kitchen towel to ensure they crisp up in the oven.
In a large mixing bowl, combine the chicken, chickpeas, broccoli florets, and sliced bell peppers.
Drizzle with olive oil and sprinkle with sea salt, black pepper, garlic powder, and smoked paprika, tossing well to coat every piece.
Spread the mixture in a single, even layer on the prepared baking sheet.
Roast for 18 to 20 minutes, or until the chicken is cooked through and the chickpeas are golden and slightly crunchy.
While the bowl base roasts, whisk together the tahini and lemon juice in a small bowl, adding a teaspoon of warm water at a time until it reaches a creamy, pourable consistency.
Remove the pan from the oven, transfer the roasted ingredients to a bowl, and drizzle the zesty tahini dressing over the top before serving.