Wash and drain the mushrooms. Make sure that they do not carry any excess water before cooking. Use towel to lightly tap and absorb any extra water.
Break the mushrooms into smaller pieces with hand or use knife (optional).
Finely chop garlic and onion.
Mix the soy sauce, 1 tablespoon oil, vinegar, and sugar separately in a small bowl.
Heat 1 tablespoon oil in the pan.
Add garlic and onion. Mix until it turns golden brown.
Add the mushrooms and stir fry for 5 mins or until they start to wilt a little.
Pour the mix of soy sauce and vinegar over the mushrooms.
Sprinkle the sesame seeds and black pepper on the top.
Cook for another 2 mins.
Close the heat. Serve with steamed rice or bread.
Enjoy!