Presoak a clay pot, top and bottom, in water for 15 minutes.
Put the halibut in the presoaked pot; add the parsley, bay leaves, onion slices, lemon, olive oil, white wine, salt, and pepper.
Cover the pot and place it in a cold oven.
Set the oven temperature at 480 degrees. Cook for 10 minutes for each inch of halibut thickness, plus 15 minutes for the pot. (Don't overcoo