1.Place noodles in a medium heatproof bowl, cover with boiling water; separate with fork, drain.
2.Meanwhile, shell and devein prawns, leaving tails intact.
3.Heat oiled wok; stir-fry shallot until browned lightly. Add curry sauce; bring to the boil. Reduce heat; simmer, uncovered, until sauce thickens slightly.
4.Add prawns to wok; simmer until prawns change colour. Add noodles and juice; stir-fry until hot, season.
5.Serve noodles sprinkled with onion.