- In a mixing bowl, combine the marinade ingredients together and add in the beef. Mix and set aside for at least 10 minutes to marinate.
- In a wok, cook the beef without oil for about a minute before transferring on to another plate to cool.
Add oil to the wok and heat over a high heat before frying the onions and the green peppers for 30 seconds.
- After this, add in the garlic and the fermented black beans and continue to fry for another 30 seconds.
- Return the beef strips back in to the wok and fry for 30 more seconds before adding in 2 tbsp of water, the sugar and salt and mix in.
- Finally, mix together the cornflour mixture ingredients and slowly pour it in a little at a time. Mix the sauce well before adding soy sauce and simmering for until the sauce thickens.
- Once the sauce has thickened, remove the wok from the heat and serve!