Place noodles in a large heatproof bowl; cover with boiling water, stand until noodles just soften, drain.
Heat 2 teaspoons of the oil in a wok; pour in egg, swirl wok to make a thin omelette. Cook until egg is just set. Remove from wok; roll omelette, cut into thin strips.
Heat remaining oil in wok; stir-fry garlic, chilli and fried onion until fragrant. Add tofu and snow peas, stir-fry for 1 minute. Add half the nuts, half the sprouts and half the green onion; stir-fry until sprouts are just wilted.
Add noodles, soy sauce and lime juice; stir-fry, tossing gently, until combined. Remove from heat; toss through omelette strips, coriander and the remaining nuts, sprouts and green onion.
Not suitable to freeze or microwave.
Cook's note: Fried shallots are available from Asian food stores and some supermarkets. For non-vegetarians, you can add prawns or chopped chicken and use fish sauce in place of soy sauce, if preferred.