Marinate the oyster mushrooms in the soy sauce, white pepper, MSG, sesame oil, and corn flour.
In a separate bowl, mix the low-sodium soy sauce, water, and brown sugar to make the sauce.
Fry the marinated mushrooms until crispy.
In a pan, sauté the onions, spring onions, garlic, and ginger.
Add the fried mushrooms and the sauce, and cook until the sauce thickens.
Serve the Mongolian Mushroom over rice.
