Add the onion and a dash of oil to a large pot over high heat. Saute the onion for 5 minutes or until it's slightly translucent. Add the garlic, ginger and miso paste. Saute for 2 minutes or until fragrant. If the ingredients start to burn, add a dash of the vegetable stock.
Add the stock, tahini, soy/tamari sauce and vinegar (if using) to the pot and reduce the heat to medium. Let the soup simmer for at least 10 minutes to allow the flavours to develop. If the soup is evaporating too quickly, add some water to the pot.
If you would like a thick soup, use a stick blender or stand blender to puree all the ingredients in the pot until smooth. If you would like a thin soup, pour the soup through a sieve into a large bowl. Discard the solids and return the soup to the pot.
Bring the soup to a boil. Add the noodles and Asian greens to the pot and cook for 5-7 minutes or until the noodles are tender.
5 minutes before serving, add the tofu to the pot and allow it to heat through.
Divide the soup, noodles, vegetables and tofu into 4 bowls. Top with carrots and serve with spring onion, sesame seeds, Japanese mixed chilli or as desired. Enjoy immediately!
If you have leftovers, seperately store all parts of the recipe in airtight containers in the fridge for up to 3 days. The soup can also be frozen for up to 1 month.