Heat up sesame oil in a large skillet over medium-high heat. Once oil is warm, add ground pork and break it up into small pieces with a spatula or wooden spoon.
1/2 tablespoon sesame oil, 1 pound ground pork
Once pork is mostly cooked through, add the garlic, ginger, onion, and mushrooms. Cook until onion and mushrooms are softened, about 5 minutes.