Take a large pot and add 600 ml dashi stock, 2 tbsp sake, 1 tbsp mirin, 3 tbsp Japanese light soy sauce (usukuchi shoyu), ¼ tsp salt and ½ tsp grated ginger root. Mix it well.
Add 200 g potherb mustard (mizuna), 4 leaves Napa cabbage, 2 fresh shiitake mushrooms, 2 sheets fried tofu pouch (aburaage) and 300 g thinly sliced pork belly to the cold broth, then place a lid on top and heat on medium.
Bring the broth to a simmer and cook with the lid on for about 10 minutes, or until the pork is cooked through and the vegetables are softened to your liking.
Grate ½ daikon radish using a Japanese oroshi grater. (Alternatively, you could use a microplane grater or similar fine grater.) Once grated, squeeze out the excess water.
Once all your ingredients are cooked, add the grated daikon to the pot and sprinkle with 2 tbsp finely chopped green onions and ground black pepper. Drizzle with 1 tbsp toasted sesame oil.
Serve and add yuzu kosho or Japanese chili powder (shichimi togarashi) to taste. Enjoy!
Notes
Feel free to substitute local ingredients, but maintain similar types - use alternative cabbages for Napa cabbage, and different mushrooms for shiitake. The cabbage is especially important as it adds water to the soup.
Choose well-marbled, thinly sliced pork cuts for the best flavor.
Both yuzu kosho and shichimi togarashi are optional condiments for those who like to add a spicy element.
For a noodle finish: after eating the vegetables, you can add cooked udon or soba noodles. Boil them separately, drain, then add to the leftover broth.
Note: While the nutritional information includes the full serving of broth, most people in Japan don't actually finish all the soup.