Wipe any dirt off mushrooms with a paper towel and cut off any larger, tough stems. Leave stems on any small, tender mushrooms. Leave the mushroom caps whole.
Reduce heat if smoking, and let mushrooms set until golden brown and starting to crisp (2-4 minutes). It's important to not move or stir the mushrooms in order to get them browned.
Flip the mushrooms and add garlic, ginger, and a little more sesame oil if needed. I like to make a divet in the middle and add the garlic, ginger, and oil.