Preheat oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Rinse quinoa and combine with 2 cups of water in a saucepan; bring to a boil, then simmer covered for 15 minutes.
In a large bowl, toss cubed chicken and sweet potatoes with olive oil, salt, pepper, garlic powder, and smoked paprika.
Spread the chicken and sweet potatoes onto the prepared baking sheet in a single layer.
Roast for 15 minutes, then add broccoli florets to the tray and roast for an additional 10 minutes or until chicken reaches an internal temperature of 165°F.
Prepare the dressing by whisking tahini, lemon juice, maple syrup, and warm water in a small bowl until smooth.
Assemble the bowls by dividing the cooked quinoa, roasted vegetables, and chicken into four equal portions.
Drizzle with the prepared tahini dressing immediately before serving.