To make your sauce, mix together the soy sauces, rice wine, vinegar, cornflour and 2 tbsps water in a small bowl. Whisk until smooth.
Slice the beef and bell pepper into thin slices. Cut the spring onions into chunks approximately 1 inch in length.
Heat the oil in a wok. When hot, add the cashews and toast for 30 seconds. Remove with a slotted spoon.
Add the beef to the wok and cook for 1 minute before adding the bell pepper and spring onions. Cook for another minute before adding the garlic and ginger.
Cook for 2 minutes until fragrant, then add the noodles, sauce and Szechuan pepper. Stir fry for two more minutes. Return the cashews to the wok, stir and serve.