Bring a pan of water to the boil, add the noodles and cook for 3 mins, adding the peas and prawns for the final min. Drain, and set aside while you heat the oil in a large frying pan.
Fry the noodles, prawns, peas, beansprouts and spring onions, tossing to coat in the oil for a few mins. Push everything to one side of the pan and pour in the egg. Stir until cooked, then mix everything well. Toss through the peanuts, soy and sweet chilli sauce so everything is combined. Scatter with the coriander and serve.