01 - Preheat the oven to 400°F. Prepare a baking dish by lining it with parchment paper or greasing lightly.
02 - Pat cod fillets dry with paper towels and arrange them in a single layer in the baking dish.
03 - Combine olive oil, parsley, dill, chives, garlic, lemon zest, lemon juice, sea salt, and black pepper in a small bowl.
04 - Spoon the herb mixture evenly over each cod fillet, gently rubbing to ensure thorough coating.
05 - Place a lemon slice atop each fillet.
06 - Bake in the oven for 15 to 18 minutes, until the fish is opaque and flakes easily with a fork.
07 - Remove the cod from the oven and let it rest for 2 minutes before serving.