Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Trim the woody ends off the asparagus spears and spread them out on one side of the prepared baking sheet.
Pat the cod fillets very dry with paper towels to ensure a better texture and place them on the other side of the sheet.
In a small bowl, whisk together the extra virgin olive oil, minced garlic, lemon zest, juice from half the lemon, sea salt, and black pepper.
Drizzle the lemon-herb mixture over both the cod and the asparagus, using your hands or a brush to coat the asparagus evenly.
Slice the remaining half of the lemon into thin rounds and place them directly on top of the cod fillets.
Bake for 12 to 15 minutes, depending on the thickness of the fish, until the cod is opaque and flakes easily with a fork.
Remove from the oven and garnish immediately with freshly chopped parsley and dill before serving.