Step 1

Cut 1lb of flank steak into thin strips across the grain. (see bulk of post for pictures)

Step 2

Place in a bowl and sprinkle with 1 1/2 tbsp of baking soda, stir gently to coat all of the beef. Then cover and let the beef marinate for 15 minutes.

Step 3

Wash off the baking soda and rinse the beef several times. (See note 5)

Step 4

Pat the beef dry with kitchen paper and set to one side.

Step 5

Add all the sauce ingredients into a large measuring cup/jug and stir well. Ensure the beef broth is cold to stop the cornstarch from clumping.

Step 6

Pour the oil into a heavy-based frying pan and place over high heat.

Step 7

While the oil is heating up, remove the roots from the green onions and chop them into 2-inch (5cm) length chunks.

Step 8

Add the green onions to the oil (be careful it can spit) and stir fry them for 1 minute to flavor the oil.

Step 9

Add the beef to the pan and cook for 1 minute, stirring constantly.

Step 10

Add in the chopped mushrooms and stir fry for a further 2 minutes.

Step 11

Add the sliced garlic and continuously stir for a minute.

Step 12

Give the prepared sauce a good stir and then pour it into the pan. The sauce will thicken quickly, so stir it to coat your stir fry and cook for 1 minute to heat through. (see note 6).

Step 13

Serve immediately.