Chop the beef into bite-sized pieces. Remove the stem from the mushrooms and break them apart with your hands.
Put the mushrooms into a pot. Spread the beef over the mushrooms. Combine the [A] ingredients, mix well, and pour over beef and mushrooms.
Cover the pot and simmer over medium heat for 3 minutes. Mix well. Remove the lid and continue simmering until the sauce has been reduced. Keep mixing while simmering.
Serve it up after it's cooled down. Arrange on a plate, top with green onions, and enjoy.
Story Behind this Recipe
Because the mushrooms give out a lot of moisture, you only need to season and simmer the ingredients to make this dish. It goes really well with rice.
-For the mushrooms: you can also use enoki or shiitake instead of shimeji and maitake. -You might feel that it tastes plain when it's freshly cooked, but the taste will be stronger after it cools down. Goes really well with rice.