Heat a frying pan over medium heat and toast the sesame seeds in it for 1 minute (you can also use toasted sesame seeds and skip this step).
Pour the toasted seeds from the pan into a large bowl.
Rehydrate the dried shiitake in boiling water for 20 minutes, then squeeze out the excess water and cut the stems to throw away, cut the rest into really small pieces. With fresh shiitake you can just cut the stem and cut them up into little pieces immediately.
Take the shiitake and add them to the frying pan, add the soy sauce and let it simmer for 2 minutes. Take the seaweed and crumble them into the same pan for about 30 seconds so it becomes infused with the flavors.
Pour this mixture into the bowl and mix well.
Next, add the miso paste and mix it thoroughly.
Lastly, add the sugar and salt. You do this last so you can taste and play with the amount of both to get the desired flavor.