Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Trim the woody ends off the asparagus and mince the garlic clove finely.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, minced garlic, dried oregano, sea salt, and black pepper.
Place the cod fillet on one side of the baking sheet and the asparagus spears on the other side.
Drizzle the lemon-herb mixture over both the fish and the asparagus, using your hands or a brush to ensure the asparagus is evenly coated.
Bake for 12 to 15 minutes, or until the cod is opaque and flakes easily with a fork and the asparagus is crisp-tender.
While the fish bakes, warm your pre-cooked quinoa in a small saucepan or microwave.
Plate the cod and asparagus over the bed of fluffy quinoa and garnish with freshly chopped parsley before serving.