Spray a wok with low-calorie cooking spray, and set on a medium heat.
Add the mushrooms to the wok and fry for 2 minutes, until they start to soften. Then add the beansprouts and fry for a further minute.
Remove the mushrooms and beansprouts from the wok and place to one side.
Wipe the wok with a piece of kitchen roll, then spray with some more low-calorie cooking spray.
Add the beaten egg to a mixing bowl, then whisk in the soy sauce and ginger. Season to taste with salt and pepper.
To the egg mixture, add the mushrooms, beansprouts, and 3/4 of the spring onions. Mix well.
Place the wok back on a medium heat, then add the egg and mushroom mix.
Using a spatula or wooden spoon, scramble the egg mix a little, until it starts to set. Then leave it to stand for 2 minutes.
Carefully flip the eggs to cook on the other side for a further 2 minutes.
Once cooked, serve, garnished with the remainder of the spring onions.