Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Pat the cod fillet dry using paper towels to remove excess moisture, ensuring the marinade adheres properly.
In a small mixing bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, minced garlic, and dried oregano.
Place the cod fillet and the trimmed asparagus spears onto the prepared baking sheet in a single layer.
Drizzle the lemon-herb mixture evenly over both the fish and the asparagus, then season everything with sea salt and black pepper.
Bake for 12 to 15 minutes, or until the cod is opaque throughout and flakes easily with a fork.
Transfer the baked cod and roasted asparagus to a plate over a bed of warm cooked quinoa.
Garnish with freshly chopped parsley and an extra squeeze of lemon if desired before serving.