2) In a medium saucepan boil the water and cook the chow mein noodles until al dente. Remove and shock in an ice bath, shake dry and toss with 2 tbsp of the oil to keep from sticking.
3) In a large saute pan or wok, heat 2 tbsp of the oil to almost smoking point and add the chicken, separating each piece upon entry. Cook until browned on all sides. Remove and keep warm.
4) In the same wok, add 2 tbsp of oil and heat until almost smoking point. Add the onions, bell peppers, carrots and celery. Saute for 2 minutes then add the mushrooms, mangetout and bean sprouts. Cook for 1 minute.
5) Add the chicken and saute for 1 minute, add the hoisin, 3 tbsp soy sauce and the sesame oil, toss and then set aside, keeping warm.
6) Heat a 30cm nonstick saute pan, add 3 tbsp of oil, heat to almost smoking point and add the chilled chow mein noodles. Cook on one side until crispy light golden brown. Flip the noodles, add another 2 tbsp of oil and cook the other side. When done, remove and drain on paper towels, while keeping warm.
7) Mix the remaining 2 tbsp of the cornflour with the chicken stock and deglaze the hot wok with the mixture. Cook to reduce by one-third.
8) Place the noodles on a rimmed serving platter, top with the chicken and vegetable saute, and pour the chicken reduction over the top. Garnish with spring onions.