Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Cut the chicken breast into 1-inch bite-sized cubes and set aside.
Chop the broccoli into small florets and dice the red bell pepper into 1-inch pieces.
In a large mixing bowl, combine the chicken, broccoli, and bell pepper.
Drizzle with olive oil and sprinkle with sea salt, black pepper, garlic powder, and smoked paprika.
Toss the mixture thoroughly until everything is evenly coated in oil and spices.
Spread the chicken and vegetables in a single layer on the prepared baking sheet.
Roast for 18-22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred edges.
Place the warm cooked quinoa into the base of a serving bowl.
Top the quinoa with the roasted chicken and vegetable mixture.
Drizzle the fresh lemon juice over the entire bowl just before serving to brighten the savory flavors.