Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Mince the garlic clove and dice the red bell pepper into one-inch pieces.
In a small mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, minced garlic, dried oregano, sea salt, and black pepper to create the marinade.
Place the chicken breast, broccoli florets, and bell pepper pieces onto the prepared sheet pan.
Drizzle the lemon-herb marinade over the chicken and vegetables, using your hands or a brush to ensure everything is evenly coated.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken is cooked through and the vegetables have developed a slight char.
While the chicken rests for a few minutes, warm the pre-cooked quinoa and spread it across the base of a large serving platter.
Slice the roasted chicken into strips and arrange it over the quinoa along with the roasted vegetables.
Garnish the entire platter with finely chopped fresh parsley before serving.