To prepare your stir-fry:

Put a large pan of water on to boil. Peel and finely slice the ginger and garlic. Finely slice the chile. Slice the chicken into finger-sized strips and lightly season with salt and pepper. Cut the ends off your scallions and finely slice. Pick the cilantro leaves and put to one side, and finely chop the cilantro stalks. Halve the bok choy lengthways. If using the mushrooms, either tear into pieces or leave whole.

To cook your stir-fry:

Preheat a wok or large frying pan on a high heat and once it’s very, very hot add a good lug of peanut oil and swirl it around. Stir in the chicken strips and cook for a couple of minutes, until the chicken browns slightly. Add the ginger, garlic, chile, cilantro stalks, mushrooms (if using), and half the scallions. Stir-fry for 30 seconds, keeping everything moving around the wok quickly. Add your noodles and bok choy to the boiling water and cook for 2 to 3 minutes, no longer. Meanwhile, add the cornstarch, water chestnuts, and their water to the wok and give it another good shake to make sure nothing sticks to the bottom. Remove from the heat and stir in 2 tablespoons of soy sauce. Halve the lime, squeeze the juice of one half into the pan, and mix well. Drain the noodles and bok choy in a colander over a bowl, reserving a little of the cooking water. Stir in the noodles and bok choy, with a little of the cooking water to loosen if necessary, and mix well. Have a taste and season with more soy sauce if needed.

To serve your stir-fry:

Use tongs to divide everything between two bowls or plates, or to lift on to one large serving platter. Spoon any juices over the top and sprinkle with the rest of the scallions and the cilantro leaves. Serve with lime wedges.