Take the tournedos out of the refrigerator and pat dry. Sprinkle both sides with the porcini mushroom powder. Set aside. Pre-heat oven to 190°C (375°F).
For the sauce: In a medium sauté pan over medium heat, cook the shallots in the cooking fat, stirring constantly for 1-2 minutes. Add the cider and reduce slightly. Add the stock. Bring to the boil. Add demi-glace sauce. Simmer for 2 minutes. Add the cream and thyme. Simmer for another 2 minutes. Remove from heat. Add the mustard and maple syrup. Stir sauce. Season with salt and pepper. Finish sauce by adding 1 tsp. of ice cider. Set aside.
Cooking the meat: Season all sides of the tournedos with salt and pepper. Pre-heat the pan with a little fat on medium high heat. Sear meat for 2 minutes on one side. Drain excess fat from the pan. Turn the meat over. Remove the pan from the heat and continue cooking in the oven for 6-8 minutes or until the meat is cooked but still pink and juicy inside (58 °C). Remove from the oven.
Drain fat. Sear the skin around the tournedos by standing them upright in a pan over medium heat for 1-2 minutes or until they become golden in colour. Transfer to a plate, remove string and let stand for 1-2 minutes before serving, loosely covered with aluminum foil. Slice. Serve on warm plates with the sauce.
Dried porcini mushrooms are Italian mushrooms used for their taste. French ceps are also very good in this recipe. Rinse them very quickly under cold water and chop finely. Available dried at IGA and other supermarkets.
Recipe from Domenico Forte, professional chef