In a bowl large enough for steaks, mix herbs, garlic and red wine. Place tenderloins in bowl, insuring that the mixture is well rubbed into the meat with your hands. Marinate for two hours at room temperature. Reserve marinade for sauce.
Steaks must be cooked immediately after finishing marinating. Do not put them into the refrigerator.
Heat oil in a cast iron skillet. Place as many steaks as well fit into the skillet without crowding. Cook to desired doneness (130 degrees for medium), turning once. Place on warm platter. Repeat until all steaks are cooked.
Add mushrooms to skillet and saute until brown -- about ten minutes. Remove from skillet. Pour off all but a tablespoon of fat from skillet. Add tablespoon of flour. Whisk into fat until a light brown roux exists. Add reserved marinade and mushrooms. Bring mixture to a boil while continuing to whisk. When the sauce is as thick as you would like, take off heat and add salt and pepper to taste.
Place a steak on each plate and cover with a couple tablespoons of sauce.
(Editor's note: In the November 2010 issue of Traverse, an incorrect image was labeled Venison Tenderloin in Shiitake Sauce.)