1. Whisk the marinade ingredients together in a bowl to dissolve the sugar. Taste and add more lime juice, sugar or fish sauce until it tastes right to you. 2. Place the steak in a container and pour ¾ of the marinade on top (Reserve the rest to use as the salad dressing later). Cover and marinate for an hour. 3. Cook the steaks until medium rare or cooked to your liking. Remove from the heat to a warm plate, cover loosely with foil and rest for 10 minutes before carving. When ready to serve, slice across the grain into thin strips. 4. Place the noodles in a heatproof bowl and pour boiling water over to cover them. Let stand about 10 minutes until soft, and drain. 5. Gently combine the beef, noodles and salad ingredients with the dressing and arrange in bowls. Garnish with extra nuts, fresh herbs, crazy peas and chopped red chillies if you like.