Heat the oil in a large wok over high heat and fry the onions for 5 minutes until soft and caramelised.
Stir in steak pieces and cook for 5 minutes.
Add garlic, ginger, fish, soy and chilli sauces. Cook for 1 minute then add half the spring onions, lime juice, chilli and herbs.
Heat the noodles as per packet instructions and arrange them into serving bowls.
Top with steak. Sprinkle with the remaining spring onions, chilli, herbs and spoon over the remaining lime juice.
Serve with a side salad.