Place the beef in a bowl with the light soy sauce, bicarb soda and cornflour. Mix well to coat the beef evenly, then set aside to marinate for 10 minutes.

Heat a wok over high heat until it begins to smoke slightly. Add the vegetable oil, then add the beef.

Spread the slices out and allow them to sear before stir-frying for a few minutes until just browned. Remove the beef from the wok and set aside.

Add the ginger, green onion and onion to the wok with a little more oil, and stir-fry for about a minute until fragrant. Add the mushrooms and stir-fry until they begin to soften.

Return the beef to the wok along with the sweet soy sauce, soy sauce, oyster sauce, caster sugar and white vinegar.

Toss everything together and stir-fry until the sauce is thick and glossy and the beef is cooked through and serve.