This was great!
1 whole pork tenderloin
1 onion chopped
4 or 5 garlic cloves minced
1/2 c soy sauce
1/2 c worchestshire
1 bottle of Thirsty Dog Leghumper porter(or any stout/porter)
Marinate for 24 hrs, throw the tenderloin on the grill.
Take the marinade in a skillet and reduce till decently thick, take half and mop your tenderloin on the grill and save the rest for after you have sliced the tenderloins into medallions, drizzle on top.
NOTE: No actual measurements were taken so this is a guess.