I heard this recipe on Nigel Barden's recipe slot on BBC Radio 2's drive time show. He said it was from Charles Campion's Food from Fire – the real barbecue book. I have tweaked the marinade quite a bit - that part was fun, I just kept making Bloody Marys (and tasting them) til I got it perfect!
While the directions below are for BBQ grilling, I have made this several times on the cooker grill and it is still delicious. I have also used the marinade with good effect for both pork and beef kebabs.