Beat the cornflour into the egg white with a fork. Pat the scallops dry and cut into quarters, then coat in the beaten egg white mixture.
Finely slice the spring onions, separating the green tops from the white stems. Mix the ginger with the white stems.
Bring a saucepan of salted water to the boil and add 1 tbsp of sunflower oil and the sugar snap peas. Cook for just 30 seconds then drain immediately.
Heat 3 tbsps sunflower oil in a wok or frying pan. Add the ginger mix and sizzle for a few seconds then add the scallops and stir fry briskly for 20 seconds.
Now add the mushrooms, stir fry briskly then add the sake, sugar snap peas and green spring onion tops. Season to taste with salt or soy sauce.
Serve immediately with some steamed rice and perhaps chilli sauce.