Heat 1 tablespoon of the oil in a wok, add the garlic and shallot and stir-fry for 1–2 minutes or until the garlic has lightly browned. Add the beans, asparagus, sweetcorn, tomato, mushrooms and soy sauce and stir-fry for another 3–4 minutes. Remove the filling from the wok and set aside. Wipe the wok clean with kitchen paper.
Pour the remaining oil into the wok and heat it, making sure the oil coats not only the base of the wok but as much of the sides as possible. Pour off any excess. Pour in the eggs, swirling them around to form a large, thin omelette. Make sure it is not sticking to the wok, adding a little more oil if necessary.
Put the filling in the middle when the omelette is almost firm and fold both sides and ends over to form an oblong parcel, constantly ensuring that the omelette is not sticking underneath.
Remove the omelette from the wok carefully and place it in a serving dish. Garnish with crispy basil, if liked, and serve immediately.