The marinade consists of only four ingredients:
minced garlic
pepper
worcestershire sauce
pesto (original recipe called for fresh oregano, but I didn't have one at that time)
Just mix everything together in a bowl and rub on the meat. Chill for an hour, though mine was kept overnight. That's it! I just made a gravy out of the pan-grilled goodness that was left after cooking the pork belly.