Beef Shank Noodle Soup

Heat oil in a medium-sized pot over medium-high heat until hot. Add the onion and carrot. Cook and stir until the onion turns golden, 3 minutes or so.
Add the water, beef braising liquid, and ketchup. Simmer until the onions turn very soft, 5 to 10 minutes.
Meanwhile, bring a separate pot of water to a boil and cook the noodles according to the package instructions. Once done, rinse the noodles with tap water for a few seconds to stop cooking, then drain and transfer them into two serving bowls.
Add the baby bok choy into the noodle boiling water. Cook for 1 minute or until the desired doneness. Transfer the bok choy onto the noodles.
If the braised beef shank is cold, add it to the broth. Cook for 1 minute or so, to warm it up.
Once the broth is ready, taste it carefully and adjust the flavor by adding a pinch of salt and the white pepper. Transfer it to the noodle bowls. Top with the braised beef shank and pickles (if using). Drizzle with chili oil and garnish with cilantro. Serve hot as a main dish.