Place the noodles in a bowl. Pour boiling water and set aside until softened.
Heat a wok or pan over heat. Add some oil and add half the egg to coat the wok in a thin layer. Cook for 1 min. Roll up and transfer to a plate. Repeat with remaining egg. Thinly slice the omelettes.
Combine the fish sauce, lemon juice and sugar in a bowl. Heat remaining oil in the wok or pan. Add garlic and chopped chilli. Cook for 1 min. Add prawns and spring onion. Cook for another 3 mins. Add sauce mixture and peanuts, noodles and omelette and toss to combine. Cook for 2 mins or until prawns are cooked through. Stir in coriander.
Top with extra spring onion, extra chopped peanuts and sliced chilli. Serve with lime wedges.