Whisk all the ingredients for the sauce together and set to one side.
Chuck the noodles into a bowl and cover with just boiled water. Leave for 8 minutes to soften and then drain. Rince with cold water and drain again.
Heat half the oil in a wok over a high heat and stir-fry the chicken for 3-4 minutes or until cooked through. Transfer to a plate.
Reheat the wok over a high and add the remaining oil. Add the onion and stir-fry for 1 minute or until a little golden. Add the garlic and chilli and stir-fry for 10 seconds until fragrant and then add the pak choi stems. Stir-fry for about a minute until just wilted.
Push everything in the wok to one side and add the eggs. Whisk in the pan for 30-40 seconds until set and then mix everything together.
Return the chicken to the pan and add the noodles, sauce, lime juice, Thai basil and pak choi leaves. Mix well and add fish sauce to taste. Start with 2 tsp and go from there. Once it's perfect, dive on in.
