Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Prepare the gremolata by finely chopping the fresh parsley and mincing the garlic clove.
In a small bowl, combine the chopped parsley, minced garlic, lemon zest, and 1 teaspoon of the olive oil, mixing until well incorporated.
Place the cod fillets and the trimmed asparagus spears onto the prepared baking sheet.
Drizzle the remaining olive oil over the fish and asparagus, then season both with sea salt and black pepper.
Evenly press the gremolata mixture onto the top of each cod fillet to create a vibrant herb crust.
Bake in the center of the oven for 12 to 15 minutes, or until the cod is opaque and flakes easily with a fork.
Divide the warm cooked quinoa between plates, top with the roasted asparagus and baked cod, and finish with a bright squeeze of fresh lemon juice.