For the steak: Trim fat and silver skin from steak.
For the marinade: Mix all ingredients together. Marinate steak and scraps for 24 hours refrigerated.
Remove steaks from marinade. Strain and reserve juices. Skim off oil and discard. Saute scraps, vegetables and spices to brown. Drain fat. Add marinade and reduce to half. Add 2 cups cold water and bring to boil. Simmer minimum 30 minutes, skimming impurities from top.
For the finished dish: In the olive oil, saute seasoned hanger steaks over high heat. Brown steaks and turn over. Add shallots and cook steaks to desired temperature (rare to medium rare) and remove. Add shiitakes, season and saute with shallots for 2 minutes. Deglaze pan with port wine and reduce to half. Add strained stock. Simmer and reduce to desired consistency. Finish with butter, rosemary and season. Slice steak 1/4-inch thick, against the grain, and on the bias. Top with sauce and serve.