Japanese Winter Stew

I kind of made this one up myself, but it's a great, warming combination of traditional Japanese ingredients with a few twists.

6 cups vegetable stock
2" piece of kombu
1/4 cup sake
1 teaspoon ginger, grated
7 ounces firm tofu (1/2 block), sliced, grilled and diced
1/2 cup shiitake mushrooms, thinly sliced
1/2 cup edamame, shelled
1/4 cup daikon radish, shredded
1 carrot, shredded
2 TB shoyu (soy)
1.5 teaspoons rayu (chili-sesame oil) or 1 tsp. sesame oil/.5 tsp chili oil
1/2 teaspoon shichimi togarashi
1/2 teaspoon white pepper
1 teaspoon sea salt
1 tsp barley miso
1 tablespoon white miso, dissolved in 2 tablespoons warm water
1 sheet nori, toasted and cut into thin strips
2 teaspoons black and white sesame seeds, toasted
prepared soba (buckwheat) noodles for each bowl

Bring stock to a simmer. Add kombu, cook for 5 minutes, and remove. Add ginger and cook for 2 minutes. Add remaining ingredients, except the miso, soba noodles, sesame seeds, and nori. Bring back to a simmer and cook for 5 more minutes, or until vegetables are crisp-tender. Mix both misos with 2 TB warm water. Immediately remove from heat and stir in miso-water mixture (cooking miso at too high a heat removes the vitamins and nutrients). Place a small handful of noodles in each bowl and ladle stew over top. Garnish each bowl with shredded nori and sesame seeds. Serves 4-6.