• Peel the ginger and cut half into thick slices.

In a large sauce pot, over high heat, combine the ginger slices with the kombu and 4 cups water. Bring to a boil, reduce to a simmer, and cook until flavorful, 8 to 10 minutes.
Remove the kombu and cut into thin slices.
While the dashi cooks, prepare the remaining vegetables.

• Finely chop the remaining ginger.
• Chop the cilantro.
• Trim the root ends of the scallions and thinly slice the white and green parts.
• Wipe the mushrooms with a damp paper towel and cut into thin slices.
• Rinse the bok choy, trim the root end, and cut crosswise into ½-inch-thick pieces.

In a mixing bowl, combine the pork, chopped ginger, cilantro, half the miso, half the scallions, and 1 teaspoon salt. With wet hands, shape the mixture into 10 to 12 meatballs.

Strain the dashi into a bowl and discard the ginger slices. Whisk ¼ cup dashi with the remaining miso. Return to the pot and, over medium heat, bring to a simmer. Add the meatballs and simmer until firm and cooked through, 8 to 10 minutes.
Add the mushrooms, bok choy, mirin-sesame sauce, and kombu slices to the dashi and cook until the mushrooms and bok choy are tender, 3 to 4 minutes. Season to taste with salt.

Transfer the soup to individual bowls. Garnish with the remaining scallions and togarashi, and serve.

Kombu is an edible kelp that can be bought fresh, dried, or frozen. It softens and expands as it cooks and delivers a rich jolt of umami. It’s also loaded with vitamins and minerals, and virtually no calories.