Mix melted butter with chopped mushrooms and cook for about five minutes. Stir, add flour and brown. Add orange juice, salt and pepper and bay leaf. Cover and simmer until sauce is creamy. Rub fillet with 2 Tbsp solid butter, sprinkle with pepper. Broil over very hot coals for 5 minutes per side. Place in a hot broiling plate, sprinkle with salt, add mushroom-orange juice sauce and cook until done to your desire, basting while it cooks.