1.Cook the udon in a pot of boiling water until just tender, 6-8 minutes. Drain and transfer to a large bowl. Add the sesame oil and toss to coat. Set aside. 2.Place the stock, shiitakes, ginger, scallions, and tamari in a large pot over medium heat. Bring to a boil, reduce the heat to low, and simmer until the shiitakes soften, about 5 minutes. 3.In a small bowl, blend the miso with 1/4 cup of the hot broth. Stir into the soup and add the noodles. Serve immediately, garnished with the parsley.