1. Combine the eggs, salt, pepper, vinegar and cornstarch mix and beat well to combine. Add the sliced spring onions and stir through the egg mix. 

2. Heat a wok over medium heat and add two-thirds of the oil, then two-thirds of the egg mixture. Cook, stirring gently, until the raw egg stops flowing into the spaces created by the stirring. Pour the remaining third of the egg mixture around the edges of the omelette. Cook for a further minute until lightly browned, then flip the omelette and drizzle the remaining oil around the wok. Cook for about a minute more, moving the omelette around so that it colours evenly. Transfer to a plate to serve.

Adam's tip Adding the egg in two stages ensures the edges of the omelette don't overcook, given the curved shape of the wok. If using a flat-bottomed wok or non-stick frying pan, you can add all the egg mixture at once.

Also try my green vegetable fried rice