Start by sautéing chopped onion and garlic in a pot with vegetable oil until they are soft and translucent.
Then, add in chopped ginger, leek, and carrot and continue to sauté for 3-5 minutes.
Once those have cooked down, add in the chopped mushrooms and sauté for another 3-5 minutes.
Add in peppercorns, cloves, star anise, and coriander seeds. Pour in 1 liter of water and bring it to a boil. Finally, let it simmer for about 30 minutes.
Add two nori leaves and let it simmer for an additional 20 minutes. Season with salt to taste.
Strain the broth into a bowl, squeezing the vegetables to extract their flavors. Return the strained broth to the pot and cook the mushrooms and bok choy until tender (the bok choy will be ready first).
Cook the rice noodles according to package instructions, which for me meant immersing the noodles in boiling water for 15 minutes.
Then, assemble the dish by placing the cooked noodles in a bowl, ladling the broth over them, and topping with cooked mushrooms, bok choy, bean sprouts, sesame seeds, chili flakes, and chopped chives.
This dish is best served hot.