My favorite, heavy duty foil, 3 thin slices of lemon, topped with 3 thin slices of onion, topped with filet,then 3 more onion topped with 3 more lemon, a sprinkle of butter buds or a small pat of butter, fold/roll the foil to form an air tight seal and cook in 500 degree oven for 20 minutes or same time on a lidded barbeque grill, it needs high heat as it steams in it's own juices. You can add a sprinkle of dill, thyme or rosemary if you must, it all tastes great. Open the end of the foil pack and let the contents slid out onto the plate, juice and all.
