Put the pork slices into a tupperware. Add 1 part sesame oil to 2 parts soy sauce, until the pork is about halfway covered. Add the garlic, a splash of mirin, the lime juice and lime rind. Give everything a good mix, cover the tupperware and put in the fridge for a couple of hours.
Watch 30 Rock.
Add a dash of sesame oil to a hot wok. Use tongs to add the pork to the wok so you don't add all the marinade at this point (otherwise you'll end up boiling the pork instead of frying it). Add the chillies and brown the pork over a high heat.
Add the rest of the marinade at this point if you like (but don't make the wok too wet). When the pork is browned, add the pak choi and the beansprouts. Toss over a high heat to shrink the pak choi and cook off the marinade.
Add the kway teow and mix everything together over a high heat. Season with soy sauce, salt and pepper to taste. Be generous with the black pepper - it really brings together the dish. Top with scallions, mix and serve.