Boil the spaghetti in a generous amount of water with a lot of salt. Break apart the shimeji and slice the leek into thin slices on the diagonal. Remove the seeds from the umeboshi and chop up well.
Heat a frying pan and melt the butter. Fry the leek over medium heat until fragrant. Add the shimeji, and stir-fry well until wilted.
Add the chicken bouillon and bring it to the boil. Add the ingredients marked ◯, and let it simmer while mixing in the umeboshi with a wooden spatula.
Add the pasta (boiled on the firm side), and let it soak up the sauce. It's done when everything has blended well. Transfer to a serving plate, and top with shredded nori, sliced green onion and shiso leaves.
Story Behind this Recipe
Long ago, I lived near a ramen shop that served ramen in umeboshi and butter. I loved it. I had cravings for it, and made this, recalling the original taste.
Adjust the amount of bouillon and soy sauce depending on the salt content of the umeboshi. I use low-salt umeboshi. If you are using umeboshi flavoured with honey, use sake instead of mirin.