Heat oil in a heavy frying pan or preheat a deep fat fryer to 190°C.
Coat beef strips with two tablespoons of vegetable oil in a bowl.
Dry fry Sichuan peppercorns in a hot pan for one minute until fragrant.
Crush peppercorns and orange zest together using a pestle and mortar.
Combine salt, rice flour, crushed peppercorns, and orange zest in a bowl.
Toss beef strips in the flour mixture to coat and discard any excess flour.
Fry beef in batches for 3 minutes until crisp and drain on kitchen paper.
Fry carrot strips for 2 minutes until softened and drain on kitchen paper.
Boil rice wine vinegar, sugar, and soy sauce in a non-reactive pan.
Add chillies, chilli flakes, and ginger; simmer until sticky and thickened.
Stir the fried beef and carrots into the sauce and cook for 2 minutes.
Stir-fry ginger, garlic, and spring onions in a hot wok for 3 minutes.
Add noodles to the wok and stir-fry for one minute to warm through.
Incorporate sesame oil, soy sauce, vinegar, and lemon juice into the noodles.
Add sesame seeds and stir-fry for 2 more minutes.
Stir in coriander and serve the beef over the noodles.