Preheat the oven to 200°C. Place the fish fillets onto the non-stick paper lined foil and fold up the edges. Place the fish parcel on a baking tray and cook in the preheated over for 10-15 minutes depending on the thickness of the fillets. Once the fish is cooked remove from the oven and set aside. While the fish is cooking, use a large saucepan to gently fry the onion in the olive oil until soft. Then add the crushed garlic and fry for 1-2 minutes more. Add the bay leaf and fresh ground black pepper to taste. Season the fish and serve.