Mix all the ingredients together in a cup or custard dish, wisk to combine with a fork. Pour 1/2 the mixture over the filet. Let marinate for at least an hour. Once coals are hot (truthfully, J does this, so I’m not entirely sure of the actual grilling process), add filet. Baste with up to two tablespoon when you turn the meat. Cook to desired doneness. You should still have a little reserve marinade. Once you’ve removed the filet from the grill, pour the rest or use as a dipping sauce.
It takes a few times to get the proportions perfect to your taste, but once you do, you’ll never go back to plain old A-1 sauce again.