Make the Dough: In a stand mixer bowl or large mixing bowl, combine the flour and salt. Gradually pour in the water while mixing on low speed (or stirring by hand). Once the dough begins to form, knead for 10 minutes until it becomes smooth. Shape it into a ball, cover, and let it rest for 30 minutes.
Portion and Rest Dough: Divide the rested dough into 8 pieces. Knead each one briefly, then roll into an oval about 2½ inches wide and 4 inches long. Arrange them on a lightly oiled surface without touching. Brush the tops with oil and cover with plastic wrap in direct contact with the dough. Let them rest for 2 hours.
Prepare the Beef: In a Dutch oven or large pot, heat neutral oil over medium-high heat. Sear the beef chunks for 4–5 minutes until browned. Stir in the tomato paste to coat the meat, cooking for 1 minute. Add scallions, ginger, garlic, star anise, and spicy bean sauce; cook another minute.
Simmer the Beef: Pour in water, Shaoxing wine, soy sauce, and sugar. Bring to a boil, then lower to a steady simmer. Cover and cook for 45 minutes. Uncover and continue simmering on medium-low for another 45 minutes, stirring occasionally. The beef is ready when fork-tender and the sauce has reduced to about 1½ cups. Stir in Sichuan peppercorns if using, then remove from heat.
Stretch and Rip the Noodles: Place a dough piece on parchment. Use a paring knife to score it down the center lengthwise without cutting all the way through. Holding both ends, stretch it into a long ribbon (20–24 inches), slapping it gently on the counter as you go. Tear the strip open along the scored line. Repeat with remaining dough and cover the noodles with a clean towel to prevent drying.
Boil the Noodles & Cabbage: In a large pot, bring water to a boil. Add cabbage and stretched noodles, stirring gently to prevent sticking. Cook for about 2 minutes, or until noodles are chewy and cabbage is tender. Drain well.
Assemble the Dish: In a large serving bowl, combine the hot noodles and cabbage. Spoon braised beef and sauce over the top. Drizzle with chili oil, light soy sauce, and black vinegar. Sprinkle with sugar, chopped scallion, and cilantro. Toss everything together and serve immediately.