Bring the broth to the boil in a pan and simmer over a low heat.
Bring a large pan of salted water to the boil. Blanch the pak choi in the boiling water for about 30 seconds, then dip in the beansprouts quickly. Remove the vegetables with a sieve so that you don’t have to drain all the water and boil new for the noodles. Rinse the vegetables immediately in cold water, they should still be very crunchy.
Heat the oil in a frying pan and fry the mince together with the spring onions, ginger and garlic. Add the fermented bean and chilli paste, sesame oil and soy sauce. Fry until the mince has coloured nicely and is crispy.
Fill four bowls with hot water to warm them. Discard the water when it’s time to plate up. Whisk a quarter of the sesame paste and chilli oil together in each bowl. Add the broth and stir.
Boil the noodles for approximately 45 seconds in the pan of water on a rolling boil. It’s best to use a noodle basket or a sieve so that you can reuse the water and quickly take out the noodles once done. You only have a window of a few seconds to make sure they’re not under- or over-cooked. Drain thoroughly and transfer the noodles to the broth bowls.
Top with the mince, pak choi, beansprouts, spring onion and pickled eggs. Serve sprinkled with the sesame seeds.