Step 1: Place fillets (pat dry) on parchment paper. Rub salt and pepper on the fillets.
Step 2: Rub some butter on the aluminum foil, and place some onions on the foil. Then place fish on top of the onions.
Step 3: Cover with remaining onion, herbs and bay leaves.
Step 4: Drizzle olive oil, lemon juice over the fish and add remaining butter. Fold and seal fish with aluminum foil.
Step 5: Place on tray and bake in a preheated 375F (190C) oven for approximately 8-10minutes (~8 minutes per pound).
Step 6: Remove from the oven and allow to stand for 3-4 minutes without opening the bag.