Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Pat the chicken breast dry with a paper towel and trim the woody ends off the asparagus spears.
In a small glass bowl, whisk together the olive oil, lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper until well combined.
Place the chicken breast on one side of the sheet pan and the asparagus on the other side.
Drizzle the lemon-herb marinade over the chicken and asparagus, using your hands or a brush to ensure the chicken is fully coated and the asparagus is tossed evenly.
Roast in the center of the oven for 18 to 22 minutes, or until the chicken reaches an internal temperature of 165°F and the asparagus is tender and slightly charred.
Allow the chicken to rest for 5 minutes before slicing it into strips.
Serve the sliced chicken and roasted asparagus over the pre-cooked quinoa to soak up any remaining lemon-herb juices.