1. To make the sauce for the meat, combine chicken stock, parsley, onions and mushrooms in a small pot and stir. Let it sit for about an hour. Add in the thyme, wine, Worcestershire sauce, balsamic vinaigrette, sugar and butter. Stir. Cook sauce on grill, reduce heat by about half and let simmer for 45 minutes to 1 hour.
2. Preheat barbecue to 500 degrees for indirect heating.
3. Spread extra-virgin olive oil, salt and pepper on each side of tenderloin.
4. Sear each side for about 2 minutes.
5. Place tenderloin on indirect heat for about 20-25 minutes.
6. Once tenderloin reaches 150 degrees with thermometer, take it off grill and wrap it in foil.
7. Pour sauce over tenderloin and serve.