Thinly slice the beef, add 2 tbsp of corn starch and water to clean the beef, it will make the beef more tender. Drain out the water (using paper towel if necessary).
Marinate the beef with soy sauce, cajun seasoning, oyster sauce, onion powder, or any other seasoning that you like. Add 2 tbsp of corn starch, and then cover with vegetable oil (to prevent the beef from drying out). Marinate for 5 minutes.
Cook the beef in boiling water, usually it takes less than 30 seconds for a small batch of beef. You can cook all of the beef at the same time, but we suggest separating them into several small batches and cook them separately. It helps to keep the pot to stay hot, shorten the cooking time, and cook evenly. Drain and place the beef in a big bowl. Add cilantro, chili peppers, sesame seeds, and garlic into the beef, pour in some hot oil to let these ingredients release the flavor. Lastly, add oyster sauce, sugar, salt, and sesame oil for extra flavor. Mix everything well and enjoy!