Trim off the tough ends of the asparagus, then cut into 1 to 2 inch long segments. Put asparagus in boiling water for 3 minutes then drain and set aside. Chop shiitake mushroom into small pieces about half-inch long and quarter-inch wide. Heat oil in a large skillet over medium heat. Add garlic and shiitake mushroom and sauté for 3 minutes. Add asparagus and stir for 2 minutes. If it becomes too dry, add some vegetable broth. Turn off heat and mix in Parmesan cheese. Season with salt and pepper (optional), serve with additional cheese.