Heat the vegetable oil in a pot, then add the star anise, cinnamon sticks, cloves, and coriander seeds. Cook until fragrant (1 min).
Roughly chop the carrot, celery, and onion. Turn up the heat, then add them to the pot, followed by the garlic cloves and ginger.
Cook for 10 minutes until the vegetables begin to char. Add the kombu, dried mushrooms, miso paste, vegetable bouillon (if using), and water. Add a large pinch of salt and sugar, then soy sauce.
Bring to a boil, then lower the heat and simmer until the broth turns golden-brown (45m-1h). Strain over a sieve into a saucepan, then season to taste and keep on low heat.
For the toppings, chop the tofu into strips, then fry until browned and season with soy sauce.
Set aside the tofu, then fry the mushrooms in oil with some soy sauce and garlic until golden.
Add the bok choy to the pan with a splash of water, cover, and steam until cooked.
Cook your noodles according to package instructions, then chop the green onions and herbs.
To serve, place noodles into bowls, add ladles of broth to cover, then add tofu, mushrooms, bok choy, herbs, green onions, chili, and sesame seeds. Enjoy!