Cut off stems of Shiitake and cut into halves. Cut the bottom of Shimeji and separate into pieces by hand. Cut the bottom 1" of Enoki and separate into small bunches.

Heat oil in a frying pan at high heat. Add garlic and mushrooms and stir-fry for a couple of minutes until softened. Add butter and soy sauce, then salt and pepper to taste. Stir for a few seconds and serve on a plate. Sprinkle chopped green onion.