Cook noodles according to package instructions. Set aside.
Heat oil in a pan. Sear beef in batches, cook for 3-4 minutes until browned all over. Remove from pan.
Add the onion and carrot, then cook, stirring, for 2-3 minutes until browned. Add the soy sauce, sugar, star anise, garlic, vinegar, beef cubes and water, sesame oil and two-thirds of the spring onion and bring to a simmer. Add beef, then cover and simmer until beef is tender.
Arrange noodles on platter. Pour a little bit of sauce over noodles and toss.
Then place tender beef short ribs on noodles. Sprinkle chopped spring onion if desired, just before serving. Serves 6-8.