Cut the Onion (1) in half, and thinly slice half and dice the other half. Slice the Fresh Ginger (1 inch) into 3 pieces. Halve the Garlic (2 clove) lengthwise. Cut the Carrot (2) into bite-sized pieces.
Combine Water (1 cup), Shaoxing Cooking Wine (3 tablespoon), Soy Sauce (3 tablespoon), ginger, garlic, Cinnamon Stick (2), Star Anise (2) and Prunes (4) in a small pot. Bring to a boil, cover, and let stand. Cut the Beef (8 ounce) into 2" pieces.
Put a large pot of water on over high heat to cook the Noodles (4 ounce) and season with Kosher Salt (to taste). Prepare the Choy Sum (1/3 bunch) by washing, slicing stems thinly, and cutting the leaves into bite-sized pieces.
Heat a large sauté pan over medium-high heat. Toss the beef in the All-Purpose Flour (2 tablespoon) and shake off excess. Add the Cooking Oil (1 tablespoon) to the sauté pan. Once the oil is heated, sear the beef withough stirring.
Turn once, and brown the other side. Remove aromatics with a slotted kitchen spoon. Add beef to liquid in sauce pot. Simmer covered for 10 minutes.
Add the carrots and diced onion. Continue to cook for 15 more minutes.
While the beef is cooking, add the sliced onion to the sauté pan that you used to sear the beef, and cook until they begin to become tender and translucent. Add the choy sum, and cook until leaves have just wilted.
Cook the pasta for 4 minutes in the boiling pot of water. Drain, and rinse with running water, then add to the pan with choy sum and onion. Stir to combine. Serve the beef and sauce over the noodle mixture and enjoy!