Precook the noodles in boiling water and set aside Blitz the garlic, onion, red chilli, ginger and half the fresh coriander together in a food processor or hand blender to make a spice paste. Add a drop of oil or soy sauce if needed. Heat the sesame oil in the wok.
Fry the shallots or onion, peppers, pak choy and mushrooms over a high heat Add the spice paste and fry for a few minutes, then add the coconut cream, the fish sauce and soy sauce and stir
Turn down the heat, add the prawns and cook for a few minutes till the prawns are cooked through. Stir through the noodles and the pak choy tops. Serve garnished with the rest of the fresh chopped coriander and a wedge of lime.