Peel garlic and cut into thin slices. Wash parsley, shake dry, and finely chop.
Mix garlic, chopped parsley, olive oil, salt, and pepper. Spread half the parsley mixture in a baking dish, place cod fillets on top, and cover with the remaining mixture. Cover the dish and refrigerate for 30 min.
While the fish refrigerates, preheat oven to 200°C / 392°F.
Cook covered in the oven for 10 min, then cover with aluminum foil and continue cooking for 10-12 min.