Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
In a small bowl, whisk together half of the olive oil, dried oregano, garlic powder, sea salt, black pepper, and lemon zest.
Rub the herb mixture evenly over the chicken breast and place it on one side of the prepared baking sheet.
Toss the broccoli florets with the remaining olive oil and a pinch of salt, then spread them out in a single layer on the other side of the sheet pan.
Roast in the oven for 18 to 22 minutes, or until the chicken reaches an internal temperature of 165°F and the broccoli is tender with crispy, charred edges.
While the chicken is roasting, gently warm the pre-cooked quinoa in a small saucepan or the microwave.
Once cooked, slice the chicken breast into strips and drizzle the fresh lemon juice over both the chicken and the broccoli.
Serve the chicken and charred broccoli over the bed of fluffy quinoa.