This recipe was found on the Appetite for China blog which features a variety of delicious Asian recipes. When developing the recipe, the blogger, Diana Kuan, was inspired by a steak teriyaki recipe in the cookbook Japanese Cooking: A Simple Art.
Salt the steaks lightly on both sides to season and extract juices.
Heat 1 tablespoon of the oil in a medium skillet over medium heat. Sauté the mushrooms and shallot for about 4 to 5 minutes, until the mushrooms and well-cooked. Set aside.
Heat the remaining 2 tablespoons of oil in a large skillet over medium-high heat. Carefully place the steaks in the pan and brown on one side uncovered, about 3 to 4 minutes. Flip the steaks and brown on the other side for another 2 minutes. Reduce the heat to medium. Splash on the sake, cover the pan, and allow the steaks to cook for another 2 to 3 minutes for medium doneness. (Add a few more minutes for medium-well or well done.).
Transfer the steaks to a plate and set aside. Add the mirin and dark soy sauce to the meat juices and sake in the pan. Cook uncovered for another 1 to 2 minutes as the meat glaze thickens (forming the teriyaki sauce). Return the steaks to the pan to coat with the sauce, about 30 seconds more on each side.
You can either serve the steaks whole or cut them against the grain into 1/2-inch slices. Spoon over with the rest of the teriyaki sauce, the mushrooms, and the shallots. Sprinkle the sesame seeds and scallions on top and serve.