Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Rinse the quinoa under cold water and place it in a small saucepan with 0.5 cups of water; bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes until fluffy.
Trim the tough, woody ends off the asparagus spears and mince the garlic cloves finely.
In a small mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, lemon zest, minced garlic, and dried oregano.
Place the cod fillet and the trimmed asparagus onto the prepared baking sheet in a single layer.
Brush the lemon-herb oil mixture generously over the top of the cod and toss the asparagus to coat evenly.
Sprinkle the sea salt and black pepper over both the fish and the vegetables.
Bake in the center of the oven for 12 to 15 minutes, or until the cod is opaque throughout and flakes easily with a fork.
Fluff the cooked quinoa with a fork and serve it as a base for the roasted cod and asparagus.