Blanch the sugar snap peas in a bowl of boiling water for 2 mins, then drain. Heat the oil in a large frying pan. Add the spring onions, garlic, ginger and chicken. Gently fry for 2-3 mins. Stir in the curry paste and cook for 1 minute more. Add the coconut milk to the pan, along with a splash of water, the lime juice, peas and sugar snap peas. Gently bubble for around 5 mins until the chicken is cooked through.
Meanwhile, cook the noodles according to the pack instructions. Drain. Stir the noodles through the sauce, scatter with coriander and serve with a wedge of lime for squeezing over.